The document discusses research on using membrane-based nanostructured metals for room temperature degradation of hazardous organics. It describes methods for synthesizing metal nanoparticles within and on membrane supports using techniques like chelation and thermal decomposition. The research shows these membrane-supported nanoparticles can effectively degrade toxic chlorinated compounds like trichloroethylene and polychlorinated biphenyls through reductive pathways.
Low Temperature Synthesis of Ba3Ta2ZnO9 (BZT) and Ba3Nb2ZnO9 (BZN) by Wet Che...IJASCSE
Powders of high microwave dielectric material Barium Zinc Tantalate (BZT) and Barium Zinc Niobate (BZN) have been prepared by wet chemical procedure at moderately low temperature ~5000C. Co-precipitate and mechanical mixtures of hydroxide of Ba(II), Ta(V)/Nb(V) & Zn(II) in 3:2:1 mole proportion on thermal decomposition, showed formation of the desired perovskite phase at 5000C. The product of co-precipitate and mechanical mixture of hydroxides heated upto7400C produced single phase BZT. Thermal decomposition of mixture was studied in static air atmosphere by TG & DTA. XRD studies on a sample heated to 500, 740, 780 & 9000C confirmed the formation of single phase BZT formation at 7400C and that of BZN at7800C.
A Simple Thermal Treatment Synthesis and Characterization of Ni-Zn Ferrite (N...IOSR Journals
Cubic structured nickel-zinc ferrite nanoparticles (Ni0.5Zn0.5Fe2O4) have been synthesized by thermal treatment method. This simple procedure employed an aqueous solution containing only metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent. The solution was thoroughly stirred for 2 hour, dried at 353 K for 3 hour, the dried material crushed into powder and calcined the powder at 873 K to remove organic substances and crystallize the particles. The microstructure properties of the prepared ferrite nanoparticles were measured using FTIR, XRD, TEM, and EDX and the magnetic properties were determined using VSM and EPR. The average particle size increased from 7 to 22 nm with the increase of calcination temperature from 723 to 873 K. The saturation magnetization, coercivity field, and g-factor increased respectively from 24 emu/g, 11 G, and 2.0673at 723 K to 38 emu/g, 60 G, and 2.1227 at 873 K. This method offers simplicity, a low cost, and an environmentally friendly operation since it produces no by-product effluents.
This lecture is based on previously read lecture "Plant Mineral Analysis", 2012. Some new points were added, especially in LOD/LOQ section. The internal standard calculation was explained. The lecture was presented in the frame of International Course "Crop Production under Saline Stress As A Result Of Climatic Changes", The Faculty of Agriculture, The Hebrew University of Jerusalem.
This document provides an overview of plant mineral analysis techniques. It discusses the essential and toxic elements analyzed in plants, sample pretreatment including sampling, decontamination, drying and grinding. Sample preparation techniques like dry ashing and wet ashing are described. The instrumentation used for analysis including XRF, AAS, flame emission spectrometry, ICP-AES, UV-VIS spectrophotometry and elemental analyzers are outlined. Key concepts like qualitative and quantitative analysis, calibration curves, limits of detection and quantitation, accuracy and precision are also summarized.
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
Solid state reactions involve reacting solids to form new solids and compounds. They have advantages like simple apparatus and low cost but also disadvantages like wide particle size distributions, need for high temperatures, and risk of contamination. Key factors that influence solid state reactions include particle size and distribution, mixing homogeneity, compaction between particles, and reaction temperature. Finer particle sizes and narrower distributions can promote more complete reactions at lower temperatures by increasing contact points between reactants.
Au nanospheres and nanorods for enzyme-free electrochemical biosensor applica...Nur Fatihah
1) The document describes the synthesis of gold nanospheres and nanorods with different morphologies for use in enzyme-free electrochemical biosensors.
2) The electrocatalytic properties and stability of biosensors using different gold nanocrystal shapes were investigated. Au nanocrystals were attached to screen-printed electrodes and used to detect hydrogen peroxide.
3) Results showed that the electrocatalytic properties and sensitivity of the biosensors depended on the morphology of the gold nanocrystals used. Biosensors using different shaped gold nanocrystals were stable for over 68 days.
Low Temperature Synthesis of Ba3Ta2ZnO9 (BZT) and Ba3Nb2ZnO9 (BZN) by Wet Che...IJASCSE
Powders of high microwave dielectric material Barium Zinc Tantalate (BZT) and Barium Zinc Niobate (BZN) have been prepared by wet chemical procedure at moderately low temperature ~5000C. Co-precipitate and mechanical mixtures of hydroxide of Ba(II), Ta(V)/Nb(V) & Zn(II) in 3:2:1 mole proportion on thermal decomposition, showed formation of the desired perovskite phase at 5000C. The product of co-precipitate and mechanical mixture of hydroxides heated upto7400C produced single phase BZT. Thermal decomposition of mixture was studied in static air atmosphere by TG & DTA. XRD studies on a sample heated to 500, 740, 780 & 9000C confirmed the formation of single phase BZT formation at 7400C and that of BZN at7800C.
A Simple Thermal Treatment Synthesis and Characterization of Ni-Zn Ferrite (N...IOSR Journals
Cubic structured nickel-zinc ferrite nanoparticles (Ni0.5Zn0.5Fe2O4) have been synthesized by thermal treatment method. This simple procedure employed an aqueous solution containing only metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent. The solution was thoroughly stirred for 2 hour, dried at 353 K for 3 hour, the dried material crushed into powder and calcined the powder at 873 K to remove organic substances and crystallize the particles. The microstructure properties of the prepared ferrite nanoparticles were measured using FTIR, XRD, TEM, and EDX and the magnetic properties were determined using VSM and EPR. The average particle size increased from 7 to 22 nm with the increase of calcination temperature from 723 to 873 K. The saturation magnetization, coercivity field, and g-factor increased respectively from 24 emu/g, 11 G, and 2.0673at 723 K to 38 emu/g, 60 G, and 2.1227 at 873 K. This method offers simplicity, a low cost, and an environmentally friendly operation since it produces no by-product effluents.
This lecture is based on previously read lecture "Plant Mineral Analysis", 2012. Some new points were added, especially in LOD/LOQ section. The internal standard calculation was explained. The lecture was presented in the frame of International Course "Crop Production under Saline Stress As A Result Of Climatic Changes", The Faculty of Agriculture, The Hebrew University of Jerusalem.
This document provides an overview of plant mineral analysis techniques. It discusses the essential and toxic elements analyzed in plants, sample pretreatment including sampling, decontamination, drying and grinding. Sample preparation techniques like dry ashing and wet ashing are described. The instrumentation used for analysis including XRF, AAS, flame emission spectrometry, ICP-AES, UV-VIS spectrophotometry and elemental analyzers are outlined. Key concepts like qualitative and quantitative analysis, calibration curves, limits of detection and quantitation, accuracy and precision are also summarized.
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
Solid state reactions involve reacting solids to form new solids and compounds. They have advantages like simple apparatus and low cost but also disadvantages like wide particle size distributions, need for high temperatures, and risk of contamination. Key factors that influence solid state reactions include particle size and distribution, mixing homogeneity, compaction between particles, and reaction temperature. Finer particle sizes and narrower distributions can promote more complete reactions at lower temperatures by increasing contact points between reactants.
Au nanospheres and nanorods for enzyme-free electrochemical biosensor applica...Nur Fatihah
1) The document describes the synthesis of gold nanospheres and nanorods with different morphologies for use in enzyme-free electrochemical biosensors.
2) The electrocatalytic properties and stability of biosensors using different gold nanocrystal shapes were investigated. Au nanocrystals were attached to screen-printed electrodes and used to detect hydrogen peroxide.
3) Results showed that the electrocatalytic properties and sensitivity of the biosensors depended on the morphology of the gold nanocrystals used. Biosensors using different shaped gold nanocrystals were stable for over 68 days.
1. Precipitation is an easy and cost-effective process to produce nano-sized particles using inexpensive source materials like inorganic chemicals.
2. Precipitation often results in hard aggregation of primary particles during washing, filtration, and drying which must be addressed.
3. Methods to prevent aggregation include controlling crystal growth, maintaining a constant pH washing solution to encourage electrostatic repulsion, and ball milling dried aggregates with less polar solvents.
2012 synthesis and photocatalytic application of ternary cu–zn–s nanoparticle...Ngoc Khuong
This document discusses a study on synthesizing and characterizing ternary Cu-Zn-S nanoparticle-sensitized TiO2 nanotube arrays (Cu-Zn-S/TiO2 NTAs) as a novel photocatalyst. Cu-Zn-S nanoparticles were deposited onto TiO2 NTAs using a pulse electrodeposition method. Under simulated solar illumination, the Cu-Zn-S/TiO2 NTAs exhibited significantly enhanced photocatalytic degradation of 2,4-D and 9-AnCOOH pollutants compared to unmodified TiO2 NTAs. After 150 minutes, 100% of 2,4-D was degraded using Cu-Zn-S/TiO2 NTAs compared to 51.8
The document summarizes the synthesis and characterization of bivalent metal chelates of 1,2-naphthoquinone dioxime. Transition metal chelates of the type M[NQO]2 where M=Hg, Cd, Zn, Pb and Ag(NQO) were synthesized. The chelates were characterized using techniques such as elemental analysis, FTIR, electronic spectra, NMR, thermogravimetry, differential scanning calorimetry and electron microscopy. Metal chelates of mercury, lead, zinc and cadmium were found to be octahedral while silver chelate was assigned as square planar. The ligand and metal chelates were screened for antimicrobial
Synthesis Of Cobalt Doped Titania Nano Materials Assisted By Anionic Heteroge...IJERA Editor
: This paper presents about the synthesis of (0.25-1.0) wt.% cobalt doped titania nanomaterials
without surfactants: pure Co2+/TiO2 and in presence of 1,4-Butane sultone and 1,3-Propane sultone Anionic
Gemini surfactants and CTAB (Heterogemini surfactant)-0.5wt.%Co2+/TiO2-HgS(1&2).The synthesized nano
photocatalysts have been characterized by using various advanced techniques like X-Ray Diffraction (XRD),
Ultraviolet-visible Diffuse Reflection Spectroscopy (UV-Vis DRS), X-ray Photoelectron Spectroscopy (XPS),
Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS), Fourier Transform Infrared
Spectroscopic Studies (FT-IR), Transmission Electron Microscopy (TEM). From the characterization studies all
the catalysts synthesized were reported in anatase phase. TEM indicates the particles size of prepared catalysts
reported with 7-10 nm and 15 nm for pure Co2+/ TiO2 catalyst. From XPS studies Cobalt was found to be in +2
oxidation state. From BET results the surface area was reported to be-89.51 and 77.93 (m2
/g) for Co2+/TiO2-
HgS(1)& Co2+/TiO2-HgS(2). From UV-DRS studies absorbance band shifted more towards visible region (red
shift). In order to find out the efficiency of the synthesized photocatalyst the photocatalytic activity studies were
carried out by degradation of Acid Red as a model azo dye pollutant in presence of the visible light irradiation.
The antibacterial activity of the synthesized catalysts against Escherichia coli was also studied. Thus from the
results 0.5wt.% Co2+/TiO2-HgS(1) exhibited highest photocatalytic activity for the degradation of azo dye Acid
Red as well as proved to be an excellent antibacterial agent
Maiyalagan,Electrochemical oxidation of methanol on pt v2 o5–c composite cata...kutty79
Platinum nanoparticles have been supported on V2O5–C composite through the reduction of chloroplatinic
acid with formaldehyde. The catalyst was characterized by X-ray diffraction and transmission electron
microscopy. Catalytic activity and stability for the oxidation of methanol were studied by using
cyclic voltammetry and chronoamperometry. Pt/V2O5–C composite anode catalyst on glassy carbon electrode
show higher electro-catalytic activity for the oxidation of methanol. High electro-catalytic activities
and good stabilities could be attributed to the synergistic effect between Pt and V2O5, avoiding the electrodes
being poisoned.
Research Paper Presentation by Ariful IslamArifulIslam665
The document summarizes a research presentation on the synthesis and characterization of new zinc, copper, and nickel complexes based on an imine ligand containing a 2-aminothiophenol moiety. Specifically, it describes the synthesis of a tridentate Schiff base ligand and its dimeric complexes with zinc, copper, and nickel ions. It then discusses the various techniques used to characterize the ligand and complexes, including IR spectroscopy, UV-Vis spectroscopy, NMR spectroscopy, conductivity measurements, computational modeling, and X-ray crystallography. The key findings are that the complexes were stable in solid and solution states, with the ligand acting as a tridentate chelating agent, and DFT calculations provided insights into their frontier
Electrocatalytic Evaluation in Methanol Oxidation Process of PtCo Nanoparticl...David Macias Ferrer
The high reactivity of methanol with platinum and the excellent catalytic activity for electro-oxidation of methanol on pure Pt especially at low temperature (below 80°C), makes this metal a suitable anodic electrocatalyst in DMFC [1]. However, it is well known that there is a series of technical problems in DMFC that limit their marketing [2]. While Pt, which is generally supported on activated carbon with large surface area such as Vulcan XC-72, is the best catalyst for the electro-oxidation of methanol, it rapidly becomes poisoned because of the intermediate species formed during the oxidation of methanol, mainly CO, since CO molecules can be chemically adsorbed on the surface of Pt and block the active sites, producing a poor kinetic of anodic methanol oxidation due to CO poisoning and a low electrocatalytic activity of electrocatalysts [3-5]. Although electrocatalysts based on Pt and Pt-Ru alloy have shown a good catalytic activity for electro-oxidation of methanol, another of the limitations in the development of DMFC for commercial applications is the high cost of both noble metals [6-7]. In this study, we report a nanocasting method of low cost to prepare NC using SBA-15 as hard template and purified sugar as carbon precursor; the inclusion of Co as a second metal, in order to reduce the amount of platinum and measure its catalytic activity in methanol oxidation process
Visible light assisted photocatalytic reduction of CO2 using a graphene oxide...Pawan Kumar
A new heteroleptic ruthenium complex containing 2-thiophenyl benzimidazole ligands was synthesized using a microwave technique and was immobilized to graphene oxide via covalent attachment. The synthesized catalyst was used for the photoreduction of carbon dioxide under visible light irradiation without using a sacrificial agent, which gave 2050 μmol g−1 cat methanol after 24 h of irradiation
Synthesis, Spectroscopic study & Biological Activity Of Some Organotin(Iv) De...IOSR Journals
Some di-and triorganotin(IV) derivatives of (2E)-N-methyl-(2
oxo1,2diphenylethylidne)hydrazinecarbothioamide synthesised by the reactions of the corresponding di and
triorganotin(IV) chlorides with the sodium salt of (2E)-N-methyl-(2-
oxo1,2diphenylethylidne)hydrazinecarbothioamide in different molar ratios. These derivatives have been
characterized by elemental analyses ,molecular weights, conductivity measurements and spectral(IR, 1H, 13C
and 119 Sn NMR) studies.
Visible Light Assisted Degradation of Eosin Yellow using Heteroatom Functiona...IJERA Editor
10 ppm EY dye were successfully photodegraded using visible light active 0.75wt% Ba & 0.25wt% Zr codoped
TiO2 nanomaterial that were synthesized by Sol-gel method as nanomaterials under irradiation for 20
minutes and characterized by various advanced instrumental techniques. The X-ray Diffraction Spectroscopic
showed that the prepared nanomaterial were in the anatase phase with 2θ at 25.3º. UV-visible Diffuse
Reflectance Spectra analysis explained that the dopants found in the TiO2, imparts a significance absorption
shift towards visible region and their exisistance were confirmed by X-ray Photoelectron Spectral data.
Quantitatively the formation of hydroxyl radical by the nanomaterial in aqueous solution under visible
light irradiation was investigated by the photoluminiscent technique. Finally the effects of different parameters
in the photocatalytic degradation of EY were established in aqueous solution
Characterization of different dopants in TiO2 Structure by Pulsed Laser Dep...sarmad
Characterization of different dopants in TiO2 Structure by Pulsed Laser Deposition
A thesis submitted By: Khaled Z.Yahya
Supervised by: Prof.Dr. Adawiya J.Haider Prof.Dr. Raad M.S.Al-Haddad
Vapor growth of binary and ternary phosphorus-based semiconductors into TiO2 ...Pawan Kumar
We report successful synthesis of low band gap inorganic polyphosphide and TiO2 heterostructures with the aid of short-way transport reactions. Binary and ternary polyphosphides (NaP7, SnIP, and (CuI)3P12) were successfully reacted and deposited into electrochemically fabricated TiO2 nanotubes. Employing vapor phase reaction deposition, the cavities of 100 μm long TiO2 nanotubes were infiltrated; approximately 50% of the nanotube arrays were estimated to be infiltrated in the case of NaP7. Intensive characterization of the hybrid materials with techniques including SEM, FIB, HR-TEM, Raman spectroscopy, XRD, and XPS proved the successful vapor phase deposition and synthesis of the substances on and inside the nanotubes. The polyphosphide@TiO2 hybrids exhibited superior water splitting performance compared to pristine materials and were found to be more active at higher wavelengths. SnIP@TiO2 emerged to be the most active among the polyphosphide@TiO2 materials. The improved photocatalytic performance might be due to Fermi level re-alignment and a lower charge transfer resistance which facilitated better charge separation from inorganic phosphides to TiO2.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
Vapor Deposition of Semiconducting Phosphorus Allotropes into TiO2 Nanotube A...Pawan Kumar
The document describes the experimental methods used to synthesize and characterize hybrid fibrous red P@TiO2 and black P@TiO2 nanotube membrane materials for photoelectrocatalytic water splitting. TiO2 nanotube membranes were fabricated by anodization and then phosphorus allotropes were deposited via chemical vapor deposition. Characterization techniques included powder XRD, SEM/EDS, STEM/EDS, Raman spectroscopy, XPS, UPS, UV-Vis spectroscopy, KPFM, and gas chromatography to confirm the formation and properties of the hybrid materials. Structural analysis by XRD and Raman spectroscopy validated the incorporation of crystalline red and black phosphorus phases within the TiO2 nanotube membranes.
Copper-Catalyzed Reactions with Diborons: From the Beginning to Recent ResultsHajime Ito
This document summarizes research from Hajime Ito's group at Hokkaido University on copper-catalyzed reactions with diborons. It describes early work in 2000 developing the first copper-catalyzed formal nucleophilic boration reaction using diboron reagents. This established a boryl-copper intermediate and the potential for ligand control of selectivity. Later work found that Xantphos ligand with copper gave high reactivity and selectivity in allylboron synthesis reactions. The group also developed the first asymmetric, copper-catalyzed allylboron synthesis using Xantphos ligand to achieve high enantioselectivity.
1) The document summarizes the synthesis and characterization of some cobalt(III) complexes containing heterocyclic nitrogen donor ligands.
2) The complexes have the general formula trans-[Co(DH)2 LCl] where DH is dimethylglyoximato and L is a heterocyclic nitrogen ligand.
3) Characterization methods included elemental analysis, conductivity, IR, 1H NMR, 13C NMR, and thermal analysis. The data indicate coordination of the ligands to the cobalt atom and a trans structure for the complexes.
Mixed-Valence Single-Atom Catalyst Derived from Functionalized GraphenePawan Kumar
Single-atom catalysts (SACs) aim at bridging the gap between homogeneous and heterogeneous catalysis. The challenge is the development of materials with ligands enabling coordination of metal atoms in different valence states, and preventing leaching or nanoparticle formation. Graphene functionalized with nitrile groups (cyanographene) is herein employed for the robust coordination of Cu(II) ions, which are partially reduced to Cu(I) due to graphene-induced charge transfer. Inspired by nature's selection of Cu(I) in enzymes for oxygen activation, this 2D mixed-valence SAC performs flawlessly in two O2-mediated reactions: the oxidative coupling of amines and the oxidation of benzylic CH bonds toward high-value pharmaceutical synthons. High conversions (up to 98%), selectivities (up to 99%), and recyclability are attained with very low metal loadings in the reaction. The synergistic effect of Cu(II) and Cu(I) is the essential part in the reaction mechanism. The developed strategy opens the door to a broad portfolio of other SACs via their coordination to various functional groups of graphene, as demonstrated by successful entrapment of FeIII/FeII single atoms to carboxy-graphene.
Synthesis and Crystal Structure of Anickel (II) and Zinc (II) Complex From 1,...IOSRJAC
:The title mononuclear nickel and zinc complexes, Ni(C11H9N4S3)2andZn(C11H9N4S3)2 .2(C3H7NO), were prepared by the reaction of Nickel(II) or Zinc(II)acetate with 1,5-bis[(2- thiophenyl)methylidene]thiocarbonohydrazide in a methanol solution. It features mono-deprotonated bisbidentate ligands, which coordinate to metal (II) ions by hydrazylN and thiocarbony lS atoms, yielding a tetracoordinated metal ions complexes. In Ni(II) complex the geometry around the metal ion is described as square planar. In the Zn(II) the metal atom shows severely tetrahedral distortion from anideal square-planar coordination geometry, as reflected by the dihedral angle between ZnN2and ZnS2 planes of 73.03(13)°. Two intramolecular hydrogen bonds are observed between the solvate dmf molecules and the coordinated ligands:N2—H2N…O1i and N6—H6N…O2 ii in this complex
A study of lattice parameters and dielectric properties against temperature a...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Recovery of silver from x ray film processing effluents by hydrogen peroxide ...Muhammad Adeel Shakoor
This document summarizes a study on recovering silver from X-ray film processing effluents using hydrogen peroxide precipitation. Key findings include:
- Hydrogen peroxide treatment is highly exothermic and rapidly precipitates over 95% of silver from effluents containing 1.1 g/L silver and 113 g/L thiosulfate when at least 37.6 g/L hydrogen peroxide is used.
- Increasing pH and adding ethylene glycol enhances silver recovery, likely by stabilizing hydrogen peroxide.
- Characterization of precipitates found silver is mainly present as fine silver sulfide.
- Hydrogen peroxide consumption oxidizes thiosulfate, increasing sulfate
This document discusses several applications of nanofiltration membranes for water treatment and separation processes. It describes using nanofiltration membranes to separate amoxicillin from pharmaceutical wastewater based on differences in molecular weight. It also discusses nanofiltration applications in the dairy industry for processes like partial demineralization of whey, lactose reduction, and detergent recovery from cleaning solutions. Additional applications discussed include removing cyanobacterial metabolites from water, concentrating copper in acid rinse water from mining operations, and treating textile wastewater.
This presentation outlines research on nano-enabled membranes for water and wastewater treatment. It discusses the global water crisis and factors contributing to it. It then introduces membrane technology and how nanomaterials can enhance membranes' performance. Several studies are summarized that developed membranes incorporating nanomaterials like iron-manganese binary oxides, TiO2, and graphene oxide to improve arsenic removal, photocatalytic degradation, and desalination, respectively. Challenges and opportunities for commercializing nano-enabled water treatment are addressed. The presentation concludes by highlighting some commercial products developed by the speaker's research center.
1. Precipitation is an easy and cost-effective process to produce nano-sized particles using inexpensive source materials like inorganic chemicals.
2. Precipitation often results in hard aggregation of primary particles during washing, filtration, and drying which must be addressed.
3. Methods to prevent aggregation include controlling crystal growth, maintaining a constant pH washing solution to encourage electrostatic repulsion, and ball milling dried aggregates with less polar solvents.
2012 synthesis and photocatalytic application of ternary cu–zn–s nanoparticle...Ngoc Khuong
This document discusses a study on synthesizing and characterizing ternary Cu-Zn-S nanoparticle-sensitized TiO2 nanotube arrays (Cu-Zn-S/TiO2 NTAs) as a novel photocatalyst. Cu-Zn-S nanoparticles were deposited onto TiO2 NTAs using a pulse electrodeposition method. Under simulated solar illumination, the Cu-Zn-S/TiO2 NTAs exhibited significantly enhanced photocatalytic degradation of 2,4-D and 9-AnCOOH pollutants compared to unmodified TiO2 NTAs. After 150 minutes, 100% of 2,4-D was degraded using Cu-Zn-S/TiO2 NTAs compared to 51.8
The document summarizes the synthesis and characterization of bivalent metal chelates of 1,2-naphthoquinone dioxime. Transition metal chelates of the type M[NQO]2 where M=Hg, Cd, Zn, Pb and Ag(NQO) were synthesized. The chelates were characterized using techniques such as elemental analysis, FTIR, electronic spectra, NMR, thermogravimetry, differential scanning calorimetry and electron microscopy. Metal chelates of mercury, lead, zinc and cadmium were found to be octahedral while silver chelate was assigned as square planar. The ligand and metal chelates were screened for antimicrobial
Synthesis Of Cobalt Doped Titania Nano Materials Assisted By Anionic Heteroge...IJERA Editor
: This paper presents about the synthesis of (0.25-1.0) wt.% cobalt doped titania nanomaterials
without surfactants: pure Co2+/TiO2 and in presence of 1,4-Butane sultone and 1,3-Propane sultone Anionic
Gemini surfactants and CTAB (Heterogemini surfactant)-0.5wt.%Co2+/TiO2-HgS(1&2).The synthesized nano
photocatalysts have been characterized by using various advanced techniques like X-Ray Diffraction (XRD),
Ultraviolet-visible Diffuse Reflection Spectroscopy (UV-Vis DRS), X-ray Photoelectron Spectroscopy (XPS),
Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS), Fourier Transform Infrared
Spectroscopic Studies (FT-IR), Transmission Electron Microscopy (TEM). From the characterization studies all
the catalysts synthesized were reported in anatase phase. TEM indicates the particles size of prepared catalysts
reported with 7-10 nm and 15 nm for pure Co2+/ TiO2 catalyst. From XPS studies Cobalt was found to be in +2
oxidation state. From BET results the surface area was reported to be-89.51 and 77.93 (m2
/g) for Co2+/TiO2-
HgS(1)& Co2+/TiO2-HgS(2). From UV-DRS studies absorbance band shifted more towards visible region (red
shift). In order to find out the efficiency of the synthesized photocatalyst the photocatalytic activity studies were
carried out by degradation of Acid Red as a model azo dye pollutant in presence of the visible light irradiation.
The antibacterial activity of the synthesized catalysts against Escherichia coli was also studied. Thus from the
results 0.5wt.% Co2+/TiO2-HgS(1) exhibited highest photocatalytic activity for the degradation of azo dye Acid
Red as well as proved to be an excellent antibacterial agent
Maiyalagan,Electrochemical oxidation of methanol on pt v2 o5–c composite cata...kutty79
Platinum nanoparticles have been supported on V2O5–C composite through the reduction of chloroplatinic
acid with formaldehyde. The catalyst was characterized by X-ray diffraction and transmission electron
microscopy. Catalytic activity and stability for the oxidation of methanol were studied by using
cyclic voltammetry and chronoamperometry. Pt/V2O5–C composite anode catalyst on glassy carbon electrode
show higher electro-catalytic activity for the oxidation of methanol. High electro-catalytic activities
and good stabilities could be attributed to the synergistic effect between Pt and V2O5, avoiding the electrodes
being poisoned.
Research Paper Presentation by Ariful IslamArifulIslam665
The document summarizes a research presentation on the synthesis and characterization of new zinc, copper, and nickel complexes based on an imine ligand containing a 2-aminothiophenol moiety. Specifically, it describes the synthesis of a tridentate Schiff base ligand and its dimeric complexes with zinc, copper, and nickel ions. It then discusses the various techniques used to characterize the ligand and complexes, including IR spectroscopy, UV-Vis spectroscopy, NMR spectroscopy, conductivity measurements, computational modeling, and X-ray crystallography. The key findings are that the complexes were stable in solid and solution states, with the ligand acting as a tridentate chelating agent, and DFT calculations provided insights into their frontier
Electrocatalytic Evaluation in Methanol Oxidation Process of PtCo Nanoparticl...David Macias Ferrer
The high reactivity of methanol with platinum and the excellent catalytic activity for electro-oxidation of methanol on pure Pt especially at low temperature (below 80°C), makes this metal a suitable anodic electrocatalyst in DMFC [1]. However, it is well known that there is a series of technical problems in DMFC that limit their marketing [2]. While Pt, which is generally supported on activated carbon with large surface area such as Vulcan XC-72, is the best catalyst for the electro-oxidation of methanol, it rapidly becomes poisoned because of the intermediate species formed during the oxidation of methanol, mainly CO, since CO molecules can be chemically adsorbed on the surface of Pt and block the active sites, producing a poor kinetic of anodic methanol oxidation due to CO poisoning and a low electrocatalytic activity of electrocatalysts [3-5]. Although electrocatalysts based on Pt and Pt-Ru alloy have shown a good catalytic activity for electro-oxidation of methanol, another of the limitations in the development of DMFC for commercial applications is the high cost of both noble metals [6-7]. In this study, we report a nanocasting method of low cost to prepare NC using SBA-15 as hard template and purified sugar as carbon precursor; the inclusion of Co as a second metal, in order to reduce the amount of platinum and measure its catalytic activity in methanol oxidation process
Visible light assisted photocatalytic reduction of CO2 using a graphene oxide...Pawan Kumar
A new heteroleptic ruthenium complex containing 2-thiophenyl benzimidazole ligands was synthesized using a microwave technique and was immobilized to graphene oxide via covalent attachment. The synthesized catalyst was used for the photoreduction of carbon dioxide under visible light irradiation without using a sacrificial agent, which gave 2050 μmol g−1 cat methanol after 24 h of irradiation
Synthesis, Spectroscopic study & Biological Activity Of Some Organotin(Iv) De...IOSR Journals
Some di-and triorganotin(IV) derivatives of (2E)-N-methyl-(2
oxo1,2diphenylethylidne)hydrazinecarbothioamide synthesised by the reactions of the corresponding di and
triorganotin(IV) chlorides with the sodium salt of (2E)-N-methyl-(2-
oxo1,2diphenylethylidne)hydrazinecarbothioamide in different molar ratios. These derivatives have been
characterized by elemental analyses ,molecular weights, conductivity measurements and spectral(IR, 1H, 13C
and 119 Sn NMR) studies.
Visible Light Assisted Degradation of Eosin Yellow using Heteroatom Functiona...IJERA Editor
10 ppm EY dye were successfully photodegraded using visible light active 0.75wt% Ba & 0.25wt% Zr codoped
TiO2 nanomaterial that were synthesized by Sol-gel method as nanomaterials under irradiation for 20
minutes and characterized by various advanced instrumental techniques. The X-ray Diffraction Spectroscopic
showed that the prepared nanomaterial were in the anatase phase with 2θ at 25.3º. UV-visible Diffuse
Reflectance Spectra analysis explained that the dopants found in the TiO2, imparts a significance absorption
shift towards visible region and their exisistance were confirmed by X-ray Photoelectron Spectral data.
Quantitatively the formation of hydroxyl radical by the nanomaterial in aqueous solution under visible
light irradiation was investigated by the photoluminiscent technique. Finally the effects of different parameters
in the photocatalytic degradation of EY were established in aqueous solution
Characterization of different dopants in TiO2 Structure by Pulsed Laser Dep...sarmad
Characterization of different dopants in TiO2 Structure by Pulsed Laser Deposition
A thesis submitted By: Khaled Z.Yahya
Supervised by: Prof.Dr. Adawiya J.Haider Prof.Dr. Raad M.S.Al-Haddad
Vapor growth of binary and ternary phosphorus-based semiconductors into TiO2 ...Pawan Kumar
We report successful synthesis of low band gap inorganic polyphosphide and TiO2 heterostructures with the aid of short-way transport reactions. Binary and ternary polyphosphides (NaP7, SnIP, and (CuI)3P12) were successfully reacted and deposited into electrochemically fabricated TiO2 nanotubes. Employing vapor phase reaction deposition, the cavities of 100 μm long TiO2 nanotubes were infiltrated; approximately 50% of the nanotube arrays were estimated to be infiltrated in the case of NaP7. Intensive characterization of the hybrid materials with techniques including SEM, FIB, HR-TEM, Raman spectroscopy, XRD, and XPS proved the successful vapor phase deposition and synthesis of the substances on and inside the nanotubes. The polyphosphide@TiO2 hybrids exhibited superior water splitting performance compared to pristine materials and were found to be more active at higher wavelengths. SnIP@TiO2 emerged to be the most active among the polyphosphide@TiO2 materials. The improved photocatalytic performance might be due to Fermi level re-alignment and a lower charge transfer resistance which facilitated better charge separation from inorganic phosphides to TiO2.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
Vapor Deposition of Semiconducting Phosphorus Allotropes into TiO2 Nanotube A...Pawan Kumar
The document describes the experimental methods used to synthesize and characterize hybrid fibrous red P@TiO2 and black P@TiO2 nanotube membrane materials for photoelectrocatalytic water splitting. TiO2 nanotube membranes were fabricated by anodization and then phosphorus allotropes were deposited via chemical vapor deposition. Characterization techniques included powder XRD, SEM/EDS, STEM/EDS, Raman spectroscopy, XPS, UPS, UV-Vis spectroscopy, KPFM, and gas chromatography to confirm the formation and properties of the hybrid materials. Structural analysis by XRD and Raman spectroscopy validated the incorporation of crystalline red and black phosphorus phases within the TiO2 nanotube membranes.
Copper-Catalyzed Reactions with Diborons: From the Beginning to Recent ResultsHajime Ito
This document summarizes research from Hajime Ito's group at Hokkaido University on copper-catalyzed reactions with diborons. It describes early work in 2000 developing the first copper-catalyzed formal nucleophilic boration reaction using diboron reagents. This established a boryl-copper intermediate and the potential for ligand control of selectivity. Later work found that Xantphos ligand with copper gave high reactivity and selectivity in allylboron synthesis reactions. The group also developed the first asymmetric, copper-catalyzed allylboron synthesis using Xantphos ligand to achieve high enantioselectivity.
1) The document summarizes the synthesis and characterization of some cobalt(III) complexes containing heterocyclic nitrogen donor ligands.
2) The complexes have the general formula trans-[Co(DH)2 LCl] where DH is dimethylglyoximato and L is a heterocyclic nitrogen ligand.
3) Characterization methods included elemental analysis, conductivity, IR, 1H NMR, 13C NMR, and thermal analysis. The data indicate coordination of the ligands to the cobalt atom and a trans structure for the complexes.
Mixed-Valence Single-Atom Catalyst Derived from Functionalized GraphenePawan Kumar
Single-atom catalysts (SACs) aim at bridging the gap between homogeneous and heterogeneous catalysis. The challenge is the development of materials with ligands enabling coordination of metal atoms in different valence states, and preventing leaching or nanoparticle formation. Graphene functionalized with nitrile groups (cyanographene) is herein employed for the robust coordination of Cu(II) ions, which are partially reduced to Cu(I) due to graphene-induced charge transfer. Inspired by nature's selection of Cu(I) in enzymes for oxygen activation, this 2D mixed-valence SAC performs flawlessly in two O2-mediated reactions: the oxidative coupling of amines and the oxidation of benzylic CH bonds toward high-value pharmaceutical synthons. High conversions (up to 98%), selectivities (up to 99%), and recyclability are attained with very low metal loadings in the reaction. The synergistic effect of Cu(II) and Cu(I) is the essential part in the reaction mechanism. The developed strategy opens the door to a broad portfolio of other SACs via their coordination to various functional groups of graphene, as demonstrated by successful entrapment of FeIII/FeII single atoms to carboxy-graphene.
Synthesis and Crystal Structure of Anickel (II) and Zinc (II) Complex From 1,...IOSRJAC
:The title mononuclear nickel and zinc complexes, Ni(C11H9N4S3)2andZn(C11H9N4S3)2 .2(C3H7NO), were prepared by the reaction of Nickel(II) or Zinc(II)acetate with 1,5-bis[(2- thiophenyl)methylidene]thiocarbonohydrazide in a methanol solution. It features mono-deprotonated bisbidentate ligands, which coordinate to metal (II) ions by hydrazylN and thiocarbony lS atoms, yielding a tetracoordinated metal ions complexes. In Ni(II) complex the geometry around the metal ion is described as square planar. In the Zn(II) the metal atom shows severely tetrahedral distortion from anideal square-planar coordination geometry, as reflected by the dihedral angle between ZnN2and ZnS2 planes of 73.03(13)°. Two intramolecular hydrogen bonds are observed between the solvate dmf molecules and the coordinated ligands:N2—H2N…O1i and N6—H6N…O2 ii in this complex
A study of lattice parameters and dielectric properties against temperature a...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Recovery of silver from x ray film processing effluents by hydrogen peroxide ...Muhammad Adeel Shakoor
This document summarizes a study on recovering silver from X-ray film processing effluents using hydrogen peroxide precipitation. Key findings include:
- Hydrogen peroxide treatment is highly exothermic and rapidly precipitates over 95% of silver from effluents containing 1.1 g/L silver and 113 g/L thiosulfate when at least 37.6 g/L hydrogen peroxide is used.
- Increasing pH and adding ethylene glycol enhances silver recovery, likely by stabilizing hydrogen peroxide.
- Characterization of precipitates found silver is mainly present as fine silver sulfide.
- Hydrogen peroxide consumption oxidizes thiosulfate, increasing sulfate
This document discusses several applications of nanofiltration membranes for water treatment and separation processes. It describes using nanofiltration membranes to separate amoxicillin from pharmaceutical wastewater based on differences in molecular weight. It also discusses nanofiltration applications in the dairy industry for processes like partial demineralization of whey, lactose reduction, and detergent recovery from cleaning solutions. Additional applications discussed include removing cyanobacterial metabolites from water, concentrating copper in acid rinse water from mining operations, and treating textile wastewater.
This presentation outlines research on nano-enabled membranes for water and wastewater treatment. It discusses the global water crisis and factors contributing to it. It then introduces membrane technology and how nanomaterials can enhance membranes' performance. Several studies are summarized that developed membranes incorporating nanomaterials like iron-manganese binary oxides, TiO2, and graphene oxide to improve arsenic removal, photocatalytic degradation, and desalination, respectively. Challenges and opportunities for commercializing nano-enabled water treatment are addressed. The presentation concludes by highlighting some commercial products developed by the speaker's research center.
Group presentation on Reverse Osmosis and Nanofiltrationzaman_866
This document summarizes reverse osmosis (RO) and nanofiltration (NF) membrane processes. Both RO and NF are pressure-driven membrane processes that separate low molecular weight solutes from water. The main difference is that NF membranes allow for the separation of some low molecular weight non-ionic molecules in addition to ionic solutes. The document discusses similarities and applications of RO and NF, as well as membrane materials, transport mechanisms, and challenges like fouling.
Nanotechnology refers to working with structures sized around 100 nanometers or smaller. Some key areas discussed in the document include the history of nanotechnology dating back to 1959, applications in areas like medicine, electronics, energy, and the environment, and both top-down and bottom-up approaches to working at the nanoscale. The future of nanotechnology is presented as holding promise for continued new applications and advancements across many fields.
Nano Filtration In Water Supply SystemsAqeel Ahamad
Man is completely dependent on water.Hence pure water is essential for many purposes.Though till now many filtration techniques have been introduced so far, using of nano technology make as the purest form of water.
Nanofiltration is a relatively recent membrane filtration process used most often with low total dissolved solids water such as surface water and fresh groundwater, with the purpose of softening ( polyvalent cation removal) and removal of disinfection by-product precursors such as natural organic matter and synthetic organic matter.
Though this paper concentrates on function of nanofiltration,it also elaborates the applications,needs and dis advantages of it.
The document describes research on photoelectrocatalytic degradation of salicylic acid using sprayed gold doped iron oxide thin films. Gold doped iron oxide films were deposited via spray pyrolysis and characterized. XRD showed the films were polycrystalline hematite. SEM showed needle-shaped grains of 100-150nm. Electrical resistivity decreased with gold doping up to 2%. The 2% gold doped film had the highest photocurrent and degraded 75% of salicylic acid in 320 minutes under visible light irradiation, making it the best photoelectrode developed in the study.
This document summarizes research on the synthesis, characterization, and application of mesoporous niobium and tantalum oxides in heterogeneous catalysis. Mesoporous transition metal oxides were synthesized using a ligand-assisted templating approach with surfactants. Characterization techniques including powder XRD, nitrogen adsorption, SEM, TEM, FT-IR and NMR confirmed the mesoporous structure. The materials were tested in benzylation, alkylation and isomerization reactions and showed high activity and selectivity due to their high surface area and acidity. Pore size effects on catalytic performance were also investigated.
This document summarizes information about ferroelectric materials and their synthesis methods. It discusses the properties of ferroelectric crystals such as barium titanate (BaTiO3), including their phase transitions and structural modifications at different temperatures. Preparation techniques for ferroelectric materials are described, such as solid state reactions and thermal decomposition. The effects of dopants like cerium dioxide on the properties of BaTiO3 ceramics are shown, including changes to Curie temperature and lattice constants. Ferroelectric ceramic-polymer composite films are also discussed as a method for producing materials with high dielectric constants.
- A new technique is presented for creating ZnO@TiO2 core-shell nano/microsphere structures using a tetrazole-based infinite coordination polymer (ICP).
- Rhodamine B-linked TiO2 nanoparticles are encapsulated within hollow Zn(btb) spheres via a solvent-induced precipitation method.
- The resulting polymeric carriers, characterized through various methods, can then be calcined to yield crystalline ZnO spheres containing encapsulated TiO2 species.
CapItalIs Fuel Cell Challenge V PresentationEngenuitySC
This document provides information on a project to develop resilient oxidation catalysts for electrochemical hydrogen pumps. The project goals were to improve the activity and durability of electrocatalysts used in hydrogen pumps by designing composite support structures. Specifically, the project involved synthesizing platinum electrocatalysts supported on carbon nanotube-titania and carbon nanotube-titanium niobium oxide composites, and testing their performance in membrane electrode assemblies. Testing showed the composite supported catalysts had better tolerance to carbon monoxide poisoning and higher carbon corrosion resistance compared to platinum on carbon nanotubes alone.
The document summarizes an internship project studying the effects of adding gold to iron nanoparticles synthesized using an arc-in-water method. Key findings include:
1) TEM analysis found that adding gold tended to reduce the average particle size of iron nanoparticles, with the smallest particles seen at around 35-45% gold content by weight.
2) XRD and EDX analysis confirmed the formation of iron-gold alloys. The ratio of alloy to gold peaks was highest at intermediate gold contents.
3) Magnetic susceptibility measurements showed that the maximum real susceptibility value occurred at similar intermediate gold compositions to those giving smallest particles and highest alloy formation.
This document discusses studies of technetium speciation using NMR and EXAFS/XANES spectroscopy during pyrometallurgical reprocessing of spent nuclear fuel. Technetium can form various oxides, oxychlorides, and chlorides of varying volatility depending on processing conditions. NMR was used to characterize technetium metal and EXAFS was used to study technetium halides and complexes. Preliminary results showed EXAFS could distinguish Tc(IV) bromide but further work is needed to characterize lower oxidation states and clusters. The goal is to understand technetium behavior to prevent accumulation and gas releases during reprocessing.
The document summarizes research on technetium metal and carbide phases. Key findings include:
1) A new orthorhombic phase of technetium metal was discovered with unit cell parameters of a = 2.805(4), b = 4.958(8), c = 4.474(5) Å for samples containing 1.38 wt.% carbon.
2) Softer conditions than previously reported were able to form technetium carbide, with a cubic phase observed at 800°C containing carbon in defective sites within the fcc structure.
3) Technetium carbide has a microhardness that is 2-2.5 times higher than pure technetium
Carbon corrosion and platinum nanoparticles ripening under open circuit poten...LandimarMendesDuarte
This document discusses a study examining the degradation of platinum nanoparticles supported on Vulcan XC72 carbon under open circuit potential conditions over 3.5 years. Characterization techniques showed that the amorphous domains of the carbon support were preferentially oxidized into CO2 during aging, while the organized domains were more slowly oxidized, producing mostly oxygen-containing surface groups and minor CO2. Over time, platinum nanoparticle aggregation and detachment from the carbon support increased due to platinum-catalyzed carbon corrosion.
Electrochemical synthesis, characterization and electrochemical behaviour of...Alexander Decker
This document summarizes the electrochemical synthesis and characterization of new conducting copolymers composed of 2-methoxyaniline and 2,3-dihydrothieno[3,4-b][1,4]dioxine-2-carboxylic acid. Four copolymers were prepared at different monomer feed concentrations and characterized using cyclic voltammetry and infrared spectroscopy. In situ conductivity measurements on the copolymers revealed two transitions in conductivity. Homopolymers and copolymers were also investigated using in situ conductivity measurements.
This document discusses various topics related to defects and properties in solid materials, including:
- Types of defects like non-stoichiometry, ionic conductivity, and intercalation chemistry.
- Cooperative phenomena such as magnetism, piezoelectricity, and superconductivity that arise from defects and ordering of ions/electrons in solids.
- Structural features of materials that enable ionic conduction like layered structures, framework solids, and intercalation hosts.
- Examples of materials that exhibit properties due to defects/structures, such as spinels, perovskites, and lithium ion battery electrodes.
The document discusses catalytic interfaces and techniques for probing their dynamics. It defines catalytic interfaces as boundaries between different phases, such as solid-gas or solid-liquid, where catalysis occurs. Dynamic processes at these interfaces include surface restructuring, oxidation/reduction, and atom migration. In situ techniques like environmental transmission electron microscopy (ETEM) and high pressure scanning tunneling microscopy allow observing these interface dynamics under reaction conditions. ETEM studies have visualized phenomena like carbon nanofiber growth, nanoparticle sintering, and surface reconstructions during catalysis. These techniques provide insights into catalyst deactivation mechanisms and ways to improve activity.
Electro oxidation of methanol on ti o2 nanotube supported platinum electrodestshankar20134
This document summarizes research on using TiO2 nanotubes as a support for platinum nanoparticles for use as an electrocatalyst in methanol fuel cells. TiO2 nanotubes were synthesized using anodic aluminum oxide as a template. Platinum nanoparticles 3-4 nm in size were uniformly dispersed on the TiO2 nanotube supports. Electrochemical testing found that platinum nanoparticles supported on TiO2 nanotubes had higher catalytic activity for methanol oxidation compared to commercial Pt/C catalysts, with mass activity over 33 mA/mg Pt versus 3.25 mA/mg Pt for Pt/C. The improved activity is attributed to the TiO2 support preventing CO poisoning of platinum sites and possible electronic interactions between
Electro oxidation of methanol on ti o2 nanotube supported platinum electrodesmadlovescience
This document summarizes research on using TiO2 nanotubes as a support for platinum nanoparticles for use as an electrocatalyst in methanol fuel cells. TiO2 nanotubes were synthesized using anodic aluminum oxide as a template. Platinum nanoparticles 3-4 nm in size were uniformly dispersed on the TiO2 nanotube supports. Electrochemical testing found that platinum nanoparticles supported on TiO2 nanotubes had higher catalytic activity for methanol oxidation compared to commercial Pt/C catalysts, with mass activity over 33 mA/mg Pt versus 3.25 mA/mg Pt for Pt/C. The improved activity is attributed to the TiO2 support preventing CO poisoning of platinum sites and possible electronic interactions between
The document summarizes research on synthesizing mesoporous titanium phosphate using a modified sol-gel method. Small angle X-ray scattering showed the formation of a liquid crystal template during synthesis. Thermal annealing was found to tune the material's bandgap, possibly by controlling residual strain in the amorphous pore walls. The mesoporous material had a larger bandgap than nonporous titanium phosphate and higher surface area. Further research aims to understand manipulating bandgap for photocatalytic applications.
Electrochemical Characterization of Electrocatalysts .pptxMabrook Saleh Amer
This document summarizes an electrochemistry workshop presentation on electrocatalyst characterization. It introduces common electrochemical characterization methods like cyclic voltammetry and discusses key figures of merit for evaluating electrocatalyst activity. Examples are provided of electrocatalyst development for important reactions like hydrogen evolution, oxygen evolution, and oxygen reduction. These include developing non-precious metal catalysts and improving catalyst stability and performance through methods like decreasing platinum loading or synthesizing metal phosphides and metal oxides on supports.
Nano-materials for Anodes in Lithium ion Battery - An introduction part 1Ahmed Hashem Abdelmohsen
The document discusses approaches to improving lithium ion battery anodes using nanomaterials. It provides a general introduction to lithium batteries and their components. Nanometal oxides like iron oxide nanoparticles coated on carbon aerogel are discussed as an anode material with high capacity and excellent cycleability. Nanostructured silicon anodes are also covered, which can provide high capacity due to silicon's ability to alloy with lithium at room temperature. Finally, graphene-coated pyrogenic carbon is presented as an anode material that provides a reversible high discharge capacity through the unique properties of graphene.
This document describes an electrochemical study of the anodic oxidation of titanium and a TA6V alloy in chromic acid electrolytes. Voltammetry and chronoamperometry experiments were conducted to investigate the formation of oxide films. In a chromic acid electrolyte without fluoride, a thin compact oxide film forms, while in a fluoride-containing electrolyte, a duplex film of a compact layer topped by a porous columnar layer grows. The voltammetry results show a breakdown of the compact film around 3 V/SCE and that alloying elements influence porous film formation. Chronoamperometry reveals the complex growth process involves residual current contributing to thickening of both layers, with overall electrochemical efficiency decreasing over
The document discusses using a LiClO4/PS-PEO-PS complex as a gate dielectric for organic thin film transistors (OTFTs). It describes how adding LiClO4 salt to the triblock copolymer induces ordered lamellar structures that provide a smooth surface and high capacitance of around 1500 nF/cm2. This makes the material promising as a gate dielectric for OTFTs, offering advantages over other dielectric materials in terms of capacitance, surface roughness, and dielectric performance.
1) The document examines how the structure of catalyst supports affects the thermal stability of platinum and ruthenium nanoparticles. 2) X-ray diffraction analysis showed that platinum and ruthenium nanoparticles supported on the ordered mesoporous SBA-15 were more thermally stable, with smaller particle sizes after heat treatments, compared to nanoparticles supported on amorphous silica materials. 3) The results indicate that catalyst support structure influences nanoparticle sintering, with ordered mesoporous materials helping to better maintain smaller particle sizes at high temperatures.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Iron and Steel Technology Roadmap - Towards more sustainable steelmaking.pdf
Bhattacharyya
1. Membrane-Based Nanostructured Metals for
Reductive Degradation of Hazardous Organics at
Room Temperature
D. Bhattacharyya (PI)*, D. Meyer, J. Xu, L. Bachas (Co-PI),
Dept. of Chemical and Materials Engineering and Dept. of
Chemistry, University of Kentucky, and S. Ritchie (Co-PI), L. Wu,
Dept. of Chemical Engineering, Univ. of Alabama
* email: db@engr.uky.edu
* phone: 859-257-2794
Project Officer: Dr. Nora Savage, US EPA
EPA Nanotechnology Grantees Workshop
August 17-20, 2004
2. Functionalized Materials and
Membranes
(Nano-domain Interactions)
Ultra-High
Capacity Metal
Sorption (Hg, Pb etc)
Reactions and Catalysis
(nanosized metals,
Vitamin B12, Enzymes)
Tunable
Separations
(with Polypeptides)
Hollman and Bhattacharyya, LANGMUIR
(2002,2004); JMS (2004)
Smuleac, Butterfield, Bhattacharyya,
Chem. of Materials (2004)
Bhattacharyya, Hestekin, et al, J. Memb. Sci. (1998)
Ritchie, Bachas, Sikdar, and Bhattacharyya, LANGMUIR (1999)
Ritchie, Bachas,Sikdar, and Bhattacharyya, ES&T (2001)
*Ahuja, Bachas, and Bhattacharyya, I&EC (2004)
3. Why Nanoparticles?
• High Surface Area
• Significant reduction in materials usage
• Reactivity (role of surface defects, role of dopants such as, Ni/Pd)
• Polymer surface coating to alter pollutant partitioning
• Alteration of reaction pathway (ex, TCE -- ethane)
• Bimetallic (role of catalysis and hydrogenation,
minimizing surface passivation)
• Enhanced particle transport in groundwater
4. Synthesis of Metal Nanoparticles in Membranes
and Polymers
• Chelation (use of polypeptides,poly(acids), and polyethyleneimine)
– Capture and borohydride reduction of metal ions using polymer films containing
polyfunctional ligands.
• Mixed Matrix Cellulose Acetate Membranes
– Incorporation of metallic salts in membrane casting solutions for dense film preparation.
Formation of particles within the membrane occurs after film formation.
– External Nanoparticle synthesis followed by membrane casting
• Thermolysis and Sonication
– Controlled growth of metal particles in polymeric matrices by decomposition of metal
carbonyl compounds thermally or by sonication.
• Di-Block Copolymers
– The use of block copolymers containing metal-interacting hydrophilic and hydrophobic
segments provide a novel approach for in-situ creation of nanostructured metals (4-5
5. Preparation of supported iron nanoparticles
The weight content of iron is 6.6% by AA (Atomic Absorption).
Water in oil micelle
5 ml NaBH4 (5.4M)
solution drop-wisely
N2
in
N2
out
Washed using methanol
CA acetone
solution
Iron nanopartilces
Mixing
Iron
naoparticles in
Cellulose
acetone solution
Ethanol bath
Casting
Synthesis reaction:
6. TEM Characterization of pre-produced iron
particles
TEM bright field image of
pre-produced iron particles
1 µm
TEM bright field image of CA
membrane-supported iron nanoparticles
7. Change of chloride ions in aqueous phase
(TCE degradation to Cl-
)
0
0.2
0.4
0.6
0.8
1
0 10 20 30 40 50
Time, hr
C/Cmax(Cmax=1.83mmol/l)
containing 27 mg pure iron per vial
containing 80 mg pure iron per vial
8. Cellulose Acetate/Nanoscale Fe-Ni Mixed-Matrix Membrane
Fe2+
/Ni2+
(aq)
Cellulose Acetate in
Acetone
Cellulose Acetate/Fe2+
/Ni2+
Mixed-Matrix
Membrane
Mixed-Matrix Membrane Preparation
NaBH4 (aq
or ethanol)
Reduction
Phase Inversion
Dry Process
Wet Process (nonsolvent gelation bath)
Water or ethanol
Meyer, Bachas, and Bhattacharyya, Env. Prog (2004)
9. Mo
+ PAA
Mo
M2+
+ 2e-
R-Cl + H+
+ 2e-
R-H + Cl-
Chlorinated organics
in water R-Cl
Selective
Sorption
In Membrane
Metal Reduction
(Borohydride or electrochemical)
M2+
Recapture with
membrane-bound PAA
Carboxylic Groups
(loss of metals and
metal hydroxide pptn.
On Mo
surface
prevented)
M2+
+ PAA-Na+
M2+
-PAA + Na+
Mo
: Nanosized Mo
in membrane phase
Nano-structured Metal Formation and Hazardous Organic
Dechlorination with Functionalized Membranes (with
simultaneous recapture/reuse of dissolved metals).
COO-
COO-
COO-
PAA:Poly-amino acid
Or Poly-acrylic acid
10. Nanoparticle Synthesis in Membrane (use of PAA)
* O S
O
O
*
Polyether sulfone
(PES)
H2C CH
C
**
OH
O
Polyacrylic acid (PAA)
* C C
H
H F
F
*
Polyvinylidene
fluoride (PVDF)
Dip Coating
Membrane support
PAA+Fe2+
+EG
NaBH4 solution
Crosslinked PAA-Fe2+
110 °C 3 hour
Uncrosslinked PAA-Fe2+
Nano Fe/Ni or Fe/Pd particles
immobilized in membrane
Cross-section
HO
OH
Ethylene glycol
(EG)
Post coating
with Ni or Pd
11. 10 20 30 40 50
0
5
10
15
20
25
30
35
40
NumberofParticles Diameter (nm)
B
(A) SEM surface image of nanoscale Fe/M particles immobilized in PAA/MF composite membrane
(reducing Fe followed by metal deposition) (100,000×); (B) Histogram from the left SEM
image of 150 nanoparticles. The average particle size is 28 nm, with the size distribution
standard deviation of 7 nm.
A
12. 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
0
5
10
15
20
25
30
35
40
NumberofParticles
Diameter (nm)
Image of Fe/Ni particles Prepared in a TEM Grid
(Ni post-Coated)
5±0.8 nm
13. Fe Ni
Fe Ni
STEM-EDS Mapping (using JOEL 2010)
Reducing Fe
followed by Ni
deposition
Simultaneous
reduction of
Fe and Ni
14. 0
0.2
0.4
0.6
0.8
1
0 0.5 1 1.5 2 2.5
Time (h)
C/C0
Blank control
PAA/PES Membrane(no particles)
Fe/Ni synthesized in solution
Fe/Ni on membrane(simultaneous reduction of Fe
and Ni)
Fe/Ni on membrane(reducing Fe followed by Ni
deposition)
TCE Dechlorination by Fe/Ni and Fe/Pd
Nanoparticles in Membrane
Metal loading:45mg/40mL
Initial TCE: 10µg/ml
Fe: Ni= 4:1 (in PES
support)
15. 0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0 0.2 0.4 0.6 0.8 1 1.2
Time (h)
-Ln(C/C0)
as×ρm
k SA=0.0813±0.002 L∙h
-1
∙m
2
, R
2
=0.989
k SA=0.1395±0.006 L∙h
-1
∙m
2
, R
2
=0.983
k SA=0.0378±0.003 L∙h
-1
∙m
2
, R
2
=0.962
k SA=0.948±0.05 L∙h
-1
∙m
2
, R
2
=0.969
Surface-Area-Normalized Dechlorination Rate (wide variation
of kSA showing the importance of surface – active sites and
role of hydrogenation)
( )Fe/Ni (simultaneous reduction);
()Fe/Ni (Ni deposition on Fe);
()Fe/Ni (solution phase)
() Fe/Pd
C: TCE concentration
kSA: surface-area-normalized
reaction rate
as: specific surface area
ρm: mass concentration of
metal
t: time
Cak
dt
dC
msSA ρ−=
Material KSA (L·h-1
·m2
)
Nano Fe 2.0×10-3
Nano Fe/Ni
(3:1)
0.098
Other source kSA*
* From B. Schrick, J.L. Blough, A.D. Jones, T.E. Mallouk,
Hydrodechlorination of Trichloroethylene to Hydrocarbons
Using Bimetallic Nickel-Iron Nanoparticles. Chem.Mater.
2002, 14, 5140-5147.
Fe/Pd
Fe/Ni
16. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 0.2 0.4 0.6 0.8 1
Weight percent Ni
kSA(Lh
-1
m
-2
)
Effect of Ni content in Fe/Ni particles on KSA
Fe Ni
Initial TCE: 20mg/L
Reaction volume: 110mL
Fe/Ni in PVDF support
(Posting coating Ni)
All experiments were performed in batch systems using nanosized
Fe/Ni particles (Post coating Ni) immobilized in PAA/PVDF membrane.
17. Reactions of 2,3,2’,5’-Tetrachlorobiphenyl (PCB)
with Fe/Pd (~30 nm) in PAA/PVDF membrane
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0 20 40 60 80 100 120 140
Time (Min)
Concentration(mM)
Biphenyl
2,3,2',5' Tetracholorobiphenyl
Metal loading:22mg/20mL
Pd = 0.4 wt%
Initial organic concentration:8.4mg/L
in 50% ethanol/water
Main intermediates at short time: 2,5,2’-
trichlorobiphenyl, 2,2’-dichlorobiphenyl,
2-chlorobiphenyl
19. Acknowledgements
US EPA- STAR Program Grant # R829621
NSF-IGERT Program
NIEHS-SBRP Program
Dow Chemical Co.
Undergrads: UK--Melody Morris, Morgan
Campbell, Alabama--Cherqueta Claiborn
Editor's Notes
Membranes provide an excellent platform for the attachment of macromolecules (high capacity ion exchange and tunable separations) and for in-situ generation of nanoparticles.
We have already demonstrated that metals can be captured at high capacity using poly-ligands (such as, PLGA). The membranes can be inexpensive cellulose or cellulose acetate-based. This Figure shows an example of an overall reductive dechlorination reaction scheme and the role of simultaneous dissolved metal ion capture/reuse for the case of functionalized membrane-based nanoparticle systems. Metal interactions reactions with PLGA are not shown in balanced form.
Here is the typical procedure for nanoparticles synthesis based on membrane domain. Basically, there are two steps involved in this procedure. First is the preparation of membrane containing metal ions as the precursor for nanoparticles. Second is the reduction of metal ions to form nanoparticles in membrane matrix. In membrane preparation part, polyacrylic acid (PAA) was used to entrap metal ions in aqueous phase, and then added to polyether sulfone (PES) support membrane by a dip-coating process. After heated at 110C for three hours, crosslinked PAA/PES composite membrane containing metal ions was obtained. Immersing the membrane into NaBH4 solution cause the formation of nanoscale metal particles. The PES support membrane is microfiltration membrane. It has open structure and large porosity which is ideal to attain high efficient utilization of available sites and the easy access to particles immobilized inside the membrane matrix. Besides, PES is a highly hydrophobic polymer, which has a strong interaction with chlorinated organics like TCE. Using PES as support platform will enhance the TCE transport from aqueous phase to membrane phase, and thus increase the overall dechlorination rate. PAA is a well known polymer for metal ions interaction because of the carboxylic group. It was largely used in ion exchange and heavy metal removal as a chelating agent.
Because of the limitation of SEM, TEM was used to study the particle size and composition in nano domain. This is a typical bright field TEM image of Fe/Ni particles inside PAA matrix. From the right figure, we know that the particle has average size 5nm, with standard deviation of 0.8nm, which is much smaller than the size in SEM image. We think this is because 30nm may be the limit of SEM. Small and individual particle less than 30nm can not be resolved in SEM. Only cluster of particles or lager one can be identified in SEM.
EDS Mapping was also performed to confirm the Fe/Ni distribution we obtained in the line profile. The EDS mapping was also done in the STEM mode. The top one is reducing Fe followed by Ni, Fe and Ni appears always together, suggesting Fe are well coated by Ni. the bottom one is simultaneous reduction of Fe and Ni, some region Fe and Ni are together, but some region Fe and Ni are separated. Therefore, both EDS line profile and mapping prove that simultaneous reduction of Fe and Ni can cause the separation of Fe and Ni.
This is the TCE dechlorination with different Fe/Ni particles. We have three Fe/Ni particles. First is reducing Fe followed by Ni, second is simultaneous reduction of Fe and Ni, third is solution phase reduction of Fe and Ni. The reaction rate by solution phase Fe and Ni is the slowest, compared to the results by membrane phase particles. For dechlorination by membrane particles, reducing Fe followed by Ni give faster reaction rate. This is because Fe is well coated by Ni. We know that in bimetallic system, the second metal should be in close contact with first metal. Separation of two metals can’t promote the reaction rate.
To get a better comparison of all the dechlorination results, the Surface-Area-Normalized Dechlorination Rate was calculated. Assuming first order reaction, As is surface area, p is the metal concentration. These can be consider as constant. The surface area was obtained according to the average particles size which was calculated based on the SEM image. As we saw before, Fe/Pd has the fastest reaction rate because Pd is more reactive than Ni. Ni deposition on Fe can make Fe and Ni in close contact, which give faster reaction rate. Solution phase Fe/Ni got slowest reaction rate. We think there are two reason for it. One is because of the agglomeration of particles which will cause less available surface area. The other is because of the PES membrane matrix. PES is hydrophobic polymer, which has strong interaction with TCE. So it can enhance the transport of TCE from aqueous phase to membrane phase. The reaction rate we are talking about is the overall reaction rate, which includes the intrinsic rate and mass transfer rate. Improving any of them can enhance the overall reaction rate. Here is the reaction rate from other source, these nanoparticles are produced in solution phase. For Fe/Ni, our ksa is close to them.
To get a better comparison of all the dechlorination results, the Surface-Area-Normalized Dechlorination Rate was calculated. Assuming first order reaction, As is surface area, p is the metal concentration. These can be consider as constant. The surface area was obtained according to the average particles size which was calculated based on the SEM image. As we saw before, Fe/Pd has the fastest reaction rate because Pd is more reactive than Ni. Ni deposition on Fe can make Fe and Ni in close contact, which give faster reaction rate. Solution phase Fe/Ni got slowest reaction rate. We think there are two reason for it. One is because of the agglomeration of particles which will cause less available surface area. The other is because of the PES membrane matrix. PES is hydrophobic polymer, which has strong interaction with TCE. So it can enhance the transport of TCE from aqueous phase to membrane phase. The reaction rate we are talking about is the overall reaction rate, which includes the intrinsic rate and mass transfer rate. Improving any of them can enhance the overall reaction rate. Here is the reaction rate from other source, these nanoparticles are produced in solution phase. For Fe/Ni, our ksa is close to them.
To get a better comparison of all the dechlorination results, the Surface-Area-Normalized Dechlorination Rate was calculated. Assuming first order reaction, As is surface area, p is the metal concentration. These can be consider as constant. The surface area was obtained according to the average particles size which was calculated based on the SEM image. As we saw before, Fe/Pd has the fastest reaction rate because Pd is more reactive than Ni. Ni deposition on Fe can make Fe and Ni in close contact, which give faster reaction rate. Solution phase Fe/Ni got slowest reaction rate. We think there are two reason for it. One is because of the agglomeration of particles which will cause less available surface area. The other is because of the PES membrane matrix. PES is hydrophobic polymer, which has strong interaction with TCE. So it can enhance the transport of TCE from aqueous phase to membrane phase. The reaction rate we are talking about is the overall reaction rate, which includes the intrinsic rate and mass transfer rate. Improving any of them can enhance the overall reaction rate. Here is the reaction rate from other source, these nanoparticles are produced in solution phase. For Fe/Ni, our ksa is close to them.