1) Titania nanopowder was prepared using a sol-gel method with titanium butoxide and nitric acid as precursors and urea as a dopant to decrease the band gap, allowing for visible light absorption.
2) Characterization with XRD, FTIR, UV-Vis, and SEM showed the powders were nanocrystalline with a band gap below 2.5 eV.
3) In photocatalytic tests, the powders significantly degraded xylenes and ethylbenzene (70% and 60% respectively) under visible light, but degraded toluene to a lesser extent (7.44%), demonstrating their photocatalytic activity.
Porosity and the Magnetic Properties of Aluminium Doped Nickel Ferriteijtsrd
The nanocrystalline particles of Aluminium Al doped nickel Ni ferrites with general formula NiAlxFe2 xO4 x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were synthesized by sol gel auto combustion technique. The formation of single phase cubic spinel was confirmed by X ray diffraction analyses. Morphological features of the samples are studied by Scanning Electron Microscopy SEM to examine the particle size, shape and homogeneity of sample. The magnetic hysteresis graphs were obtained to understand their magnetic behaviours. The relative permeability µr of AlNi ferrite samples shows a decrease for all samples as Al content increases. Sandar Oo | Ye Wint Tun | Shwe Zin Oo "Porosity and the Magnetic Properties of Aluminium Doped Nickel Ferrite" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25240.pdfPaper URL: https://www.ijtsrd.com/physics/other/25240/porosity-and-the-magnetic-properties-of-aluminium-doped-nickel-ferrite/sandar-oo
Multi-layered materials are commonly used in various industries and may alter the mechanical, acoustic and optical properties of materials. Identifying the chemical composition of different layers by studying the cross section of a multi-layered film is important in research and development of composite materials. This presentation showcases the use of an FTIR microscope to acquire high-resolution data of the cross section of composite films. Analysis of the FTIR spectra helps to understand the formulation of different layers of polymer film.
Greener cum chemical synthesis and characterization of Mg doped ZnS nanoparti...IJERA Editor
In the present investigations, high-quality Mg doped ZnS nanoparticles were synthesized by Greener cum
chemical process with the assistance of polyvinyl pyrrolidone (PVP) with two different Mg concentrations.
Doping of Mg metal in nanoparticles were found to be a good technique for tuning the band gap of ZnS
nanoparticles. Simultaneously, Mg doping also inhibited the growth of particle size and it decreased from 33.2
nm to 18.3 nm with the increase in doping concentration from 0% to 5%. Band gap was found to rise from 3.12
eV to 3.38 eV and photoluminescence studies exposed that visible Photoluminescence (PL) emission was
improved with doping concentration. The nanoparticles have been characterized by Field Emission Scanning
Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy,
Ultra Violet visible (UV–vis) spectroscopy, and Energy Dispersive X-ray Analysis (EDAX).
Synthesis & Bio-Evaluation of 4-Amino-5-Benzyl-2, 4-Dihydro-3H-1, 2, 4-Triazo...IJERA Editor
Synthesis of 4-amino-5-benzyl-2,4-dihydro-3H-1,2,4-triazole-3-thione Capped Silver NanoParticles by a simple procedure. Spherical shaped Capped Ag-NPs with average size of 14.65 nm are obtained by the treatment of aqueous silver ions with hot ethanolic solution of 4-amino-5-benzyl-2,4-dihydro-3H-1,2,4-triazole-3-thione as Stabilizing/Reducing agent. The Nanoparticles are characterized using TEM, XRD and FTIR studies. The synthesized Nanoparticles were tested for in vitro antimicrobial activity at concentrations of 50, 100, 200 μg /ml. The Nanoparticles showed good activity, nearly equal to the inhibition zone value of ciprofloxacin, against the E.coli bacteria. For the antifungal activity, the compound showed equipotent activity against A.niger.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Porosity and the Magnetic Properties of Aluminium Doped Nickel Ferriteijtsrd
The nanocrystalline particles of Aluminium Al doped nickel Ni ferrites with general formula NiAlxFe2 xO4 x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were synthesized by sol gel auto combustion technique. The formation of single phase cubic spinel was confirmed by X ray diffraction analyses. Morphological features of the samples are studied by Scanning Electron Microscopy SEM to examine the particle size, shape and homogeneity of sample. The magnetic hysteresis graphs were obtained to understand their magnetic behaviours. The relative permeability µr of AlNi ferrite samples shows a decrease for all samples as Al content increases. Sandar Oo | Ye Wint Tun | Shwe Zin Oo "Porosity and the Magnetic Properties of Aluminium Doped Nickel Ferrite" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25240.pdfPaper URL: https://www.ijtsrd.com/physics/other/25240/porosity-and-the-magnetic-properties-of-aluminium-doped-nickel-ferrite/sandar-oo
Multi-layered materials are commonly used in various industries and may alter the mechanical, acoustic and optical properties of materials. Identifying the chemical composition of different layers by studying the cross section of a multi-layered film is important in research and development of composite materials. This presentation showcases the use of an FTIR microscope to acquire high-resolution data of the cross section of composite films. Analysis of the FTIR spectra helps to understand the formulation of different layers of polymer film.
Greener cum chemical synthesis and characterization of Mg doped ZnS nanoparti...IJERA Editor
In the present investigations, high-quality Mg doped ZnS nanoparticles were synthesized by Greener cum
chemical process with the assistance of polyvinyl pyrrolidone (PVP) with two different Mg concentrations.
Doping of Mg metal in nanoparticles were found to be a good technique for tuning the band gap of ZnS
nanoparticles. Simultaneously, Mg doping also inhibited the growth of particle size and it decreased from 33.2
nm to 18.3 nm with the increase in doping concentration from 0% to 5%. Band gap was found to rise from 3.12
eV to 3.38 eV and photoluminescence studies exposed that visible Photoluminescence (PL) emission was
improved with doping concentration. The nanoparticles have been characterized by Field Emission Scanning
Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy,
Ultra Violet visible (UV–vis) spectroscopy, and Energy Dispersive X-ray Analysis (EDAX).
Synthesis & Bio-Evaluation of 4-Amino-5-Benzyl-2, 4-Dihydro-3H-1, 2, 4-Triazo...IJERA Editor
Synthesis of 4-amino-5-benzyl-2,4-dihydro-3H-1,2,4-triazole-3-thione Capped Silver NanoParticles by a simple procedure. Spherical shaped Capped Ag-NPs with average size of 14.65 nm are obtained by the treatment of aqueous silver ions with hot ethanolic solution of 4-amino-5-benzyl-2,4-dihydro-3H-1,2,4-triazole-3-thione as Stabilizing/Reducing agent. The Nanoparticles are characterized using TEM, XRD and FTIR studies. The synthesized Nanoparticles were tested for in vitro antimicrobial activity at concentrations of 50, 100, 200 μg /ml. The Nanoparticles showed good activity, nearly equal to the inhibition zone value of ciprofloxacin, against the E.coli bacteria. For the antifungal activity, the compound showed equipotent activity against A.niger.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Textile dyes have been reported as causing various stages of contact dermatitis. Reactive dyes are widely applied in dyeing cellulose fiber-based textiles (100% cotton), skin fibers (hemp, flax), regenerated cellulose (cellulose acetate, viscose), protein fibers (natural silk, wool). The human body comes in contact daily with such compounds. This aspect is important for elucidating their biological effects on the human body, in correlation with Physico-chemical properties. Dyes are chemical compounds containing chromophore and autochrome groups. The authors herein report results concerning the influence of UV irradiation with λ > 300 nm on the structure and properties of different colored textiles. Subjects to study were textiles painted with four azo-triazine-based dyes which were exposed to 100 h UV irradiation time and irradiation dose values up to 3500 J cm-2. The five azo dyes were: reactive orange 13, reactive red 183, reactive yellow 143, reactive blue 204, and reactive red 2. Structural modifications as a result of irradiation were undertaken by UV-Vis spectroscopy. It was observed that during UV exposure there occurred partial dyes detachment from the textiles, accompanied by glucosidic units and dye photodecomposition by C–N bond scission and degradation of aromatic entities and azo-based chromophores. Color modifications were also investigated. Color differences significantly increased with the irradiation dose for all the studied samples.
Structural and optical properties of molybdenum doped BiVO4 powders-Cce 2014MERUPO Victor
Molybdenum-doped BiVO4 powders were prepared by Sol-gel method. Monoclinic scheelite phase was confirmed by X-ray diffraction (XRD) patterns and micro-Raman vibrational bands. Substitution of molybdenum in crystal sites of BiVO4 was evidenced from XRD by higher angle 2θ shift of the characteristic peak (-121) and from Raman showing lower frequency shift of dominant peak from 831 to 822 cm-1 which corresponds to V-O symmetric stretching mode. The morphological properties were analyzed by FE-SEM which confirmed the formation of homogeneous spherical shaped particles with size around 200-300nm. Optical properties were analyzed by Diffuse Reflectance Spectra which show higher absorption in the range of 550-850nm. Optical band gap energies were calculated by using Kubelka-Munk formula, i.e, 2.46 eV for 2 wt% Mo-BiVO4 and 2.47eV for undoped BiVO4. This confirms that Mo-BiVO4 particles have the same band gap but induce higher absorption in the visible light region compared to BiVO4
Nanoparticles are solid colloidal particles ranging in size from 10 to 1000 nm.
Nanoparticles are made of a macromolecular material which can be of synthetic or natural origin.
Synthesis of Cobalt ferrite by Solid Reaction Methodsank_sanjay
Cobalt ferrite nano-crystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3 on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900˚C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000˚C, the reaction was completed and single phase CoFe2O4 with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained.
Optical and Electrical Properties of TiO2 Doped Fe2O3 Thin Film Prepared by S...IJAEMSJORNAL
In this work, iron oxide (Fe2O3) and titanium oxide (TiO2) doping (Fe2O3) thin films have been prepared by spray pyrolysis technique (SPT) on a glass substrate. We have studied the effects of various doping percentage of (TiO2) on (Fe2O3) optical and electrical properties. The optical parameters of the prepared films as absorbance, absorption coefficient, optical energy gap and refractive index have been calculated for all prepared films. D.C conductivity and Hall effect for all films are measured. The results showed that absorbance of prepared films decreases with increasing percentage of (TiO2) this lead to increase the energy gap and conductivity decreased with increasing of percentage of (TiO2) as well as the results showed throughout the study that all films have tow activation energy, its value increase with increasing of percentage of (TiO2). Hall effect measurement showed all films have n-type conductivity.
A polymethyl-methacrylate (PMMA) acrylic sample cell using flow injection is developed in this research for the determination of nitrite in an aqueous media. The research focuses on exhibiting direct absorbance spectrophotometry of nitrite using concentration of samples ranging from 0.1078 to 1.725 ppm. Nitrite determination is done colorimetrically using the Greiss reagent method. This method is based on the reaction of nitrite with sulphanilamide acid and N-1-napthylamine (NED) utilizing diazo coupling, and a syringe is used to administer the nitrite solution. The sample cell being used possesses a diameter of 1
mm with an overall size of 7.35×22 mm2. To gauge the direct absorbance, a wavelength range from 400 to 650 nm has been selected for the testing, and the maximum absorbance is found to be at 545 nm. The validity of the proposed cell is explained in this letter.
Photo-induced reduction of CO2 using a magnetically separable Ru-CoPc@TiO2@Si...Pawan Kumar
An efficient photo-induced reduction of CO2 using magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4
as a heterogeneous catalyst in which CoPc and Ru(bpy)2phene complexes were attached to a solid
support via covalent attachment under visible light is described. The as-synthesized catalyst was characterized
by a series of techniques including FTIR, UV-Vis, XRD, SEM, TEM, etc. and subsequently tested for
the photocatalytic reduction of carbon dioxide using triethylamine as a sacrificial donor and water as a
reaction medium. The developed photocatalyst exhibited a significantly higher catalytic activity to give a
methanol yield of 2570.78 μmol per g cat after 48 h.
Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries.
Transparent and Conducting TiO2 : Nb Thin Films Prepared by Spray Pyrolysis T...arj_online
To date, only sputtering and pulsed laser deposition (PLD) techniques have been employed
successfully to fabricate highly conducting and transparent TiO2:Nb (TNO) films. In this article, we demonstrate
that transparent and conducting
TiO2
: Nb
films can be made by the spray pyrolysis technique. The films were
deposited on Corning 7059 glass substrates at 500
15˚C using an alcoholic precursor solution consisting of
titanium (iv) isopropoxide and
NbCl5
. The influence of increasing
Nb
concentration on the electrical, optical
and structural properties was investigated. The minimum resistivity, 3.36
-3 10
Ω cm, for
Ti1-xNbxO2
film (x
= 0.15) was obtained after 1 hour post deposition annealing in hydrogen atmosphere at 500˚C. The x-ray
diffraction of hydrogen annealed films showed a polycrystalline anatase (004)-oriented phase without any second
phases. The optical band gap for undoped and doped films lay in the range 3.38 – 3.47 eV. Using dispersion
analysis, optical constants were determined from spectro-photometric measurements for films on glass.
Textile dyes have been reported as causing various stages of contact dermatitis. Reactive dyes are widely applied in dyeing cellulose fiber-based textiles (100% cotton), skin fibers (hemp, flax), regenerated cellulose (cellulose acetate, viscose), protein fibers (natural silk, wool). The human body comes in contact daily with such compounds. This aspect is important for elucidating their biological effects on the human body, in correlation with Physico-chemical properties. Dyes are chemical compounds containing chromophore and autochrome groups. The authors herein report results concerning the influence of UV irradiation with λ > 300 nm on the structure and properties of different colored textiles. Subjects to study were textiles painted with four azo-triazine-based dyes which were exposed to 100 h UV irradiation time and irradiation dose values up to 3500 J cm-2. The five azo dyes were: reactive orange 13, reactive red 183, reactive yellow 143, reactive blue 204, and reactive red 2. Structural modifications as a result of irradiation were undertaken by UV-Vis spectroscopy. It was observed that during UV exposure there occurred partial dyes detachment from the textiles, accompanied by glucosidic units and dye photodecomposition by C–N bond scission and degradation of aromatic entities and azo-based chromophores. Color modifications were also investigated. Color differences significantly increased with the irradiation dose for all the studied samples.
Structural and optical properties of molybdenum doped BiVO4 powders-Cce 2014MERUPO Victor
Molybdenum-doped BiVO4 powders were prepared by Sol-gel method. Monoclinic scheelite phase was confirmed by X-ray diffraction (XRD) patterns and micro-Raman vibrational bands. Substitution of molybdenum in crystal sites of BiVO4 was evidenced from XRD by higher angle 2θ shift of the characteristic peak (-121) and from Raman showing lower frequency shift of dominant peak from 831 to 822 cm-1 which corresponds to V-O symmetric stretching mode. The morphological properties were analyzed by FE-SEM which confirmed the formation of homogeneous spherical shaped particles with size around 200-300nm. Optical properties were analyzed by Diffuse Reflectance Spectra which show higher absorption in the range of 550-850nm. Optical band gap energies were calculated by using Kubelka-Munk formula, i.e, 2.46 eV for 2 wt% Mo-BiVO4 and 2.47eV for undoped BiVO4. This confirms that Mo-BiVO4 particles have the same band gap but induce higher absorption in the visible light region compared to BiVO4
Nanoparticles are solid colloidal particles ranging in size from 10 to 1000 nm.
Nanoparticles are made of a macromolecular material which can be of synthetic or natural origin.
Synthesis of Cobalt ferrite by Solid Reaction Methodsank_sanjay
Cobalt ferrite nano-crystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3 on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900˚C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000˚C, the reaction was completed and single phase CoFe2O4 with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained.
Optical and Electrical Properties of TiO2 Doped Fe2O3 Thin Film Prepared by S...IJAEMSJORNAL
In this work, iron oxide (Fe2O3) and titanium oxide (TiO2) doping (Fe2O3) thin films have been prepared by spray pyrolysis technique (SPT) on a glass substrate. We have studied the effects of various doping percentage of (TiO2) on (Fe2O3) optical and electrical properties. The optical parameters of the prepared films as absorbance, absorption coefficient, optical energy gap and refractive index have been calculated for all prepared films. D.C conductivity and Hall effect for all films are measured. The results showed that absorbance of prepared films decreases with increasing percentage of (TiO2) this lead to increase the energy gap and conductivity decreased with increasing of percentage of (TiO2) as well as the results showed throughout the study that all films have tow activation energy, its value increase with increasing of percentage of (TiO2). Hall effect measurement showed all films have n-type conductivity.
A polymethyl-methacrylate (PMMA) acrylic sample cell using flow injection is developed in this research for the determination of nitrite in an aqueous media. The research focuses on exhibiting direct absorbance spectrophotometry of nitrite using concentration of samples ranging from 0.1078 to 1.725 ppm. Nitrite determination is done colorimetrically using the Greiss reagent method. This method is based on the reaction of nitrite with sulphanilamide acid and N-1-napthylamine (NED) utilizing diazo coupling, and a syringe is used to administer the nitrite solution. The sample cell being used possesses a diameter of 1
mm with an overall size of 7.35×22 mm2. To gauge the direct absorbance, a wavelength range from 400 to 650 nm has been selected for the testing, and the maximum absorbance is found to be at 545 nm. The validity of the proposed cell is explained in this letter.
Photo-induced reduction of CO2 using a magnetically separable Ru-CoPc@TiO2@Si...Pawan Kumar
An efficient photo-induced reduction of CO2 using magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4
as a heterogeneous catalyst in which CoPc and Ru(bpy)2phene complexes were attached to a solid
support via covalent attachment under visible light is described. The as-synthesized catalyst was characterized
by a series of techniques including FTIR, UV-Vis, XRD, SEM, TEM, etc. and subsequently tested for
the photocatalytic reduction of carbon dioxide using triethylamine as a sacrificial donor and water as a
reaction medium. The developed photocatalyst exhibited a significantly higher catalytic activity to give a
methanol yield of 2570.78 μmol per g cat after 48 h.
Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries.
Transparent and Conducting TiO2 : Nb Thin Films Prepared by Spray Pyrolysis T...arj_online
To date, only sputtering and pulsed laser deposition (PLD) techniques have been employed
successfully to fabricate highly conducting and transparent TiO2:Nb (TNO) films. In this article, we demonstrate
that transparent and conducting
TiO2
: Nb
films can be made by the spray pyrolysis technique. The films were
deposited on Corning 7059 glass substrates at 500
15˚C using an alcoholic precursor solution consisting of
titanium (iv) isopropoxide and
NbCl5
. The influence of increasing
Nb
concentration on the electrical, optical
and structural properties was investigated. The minimum resistivity, 3.36
-3 10
Ω cm, for
Ti1-xNbxO2
film (x
= 0.15) was obtained after 1 hour post deposition annealing in hydrogen atmosphere at 500˚C. The x-ray
diffraction of hydrogen annealed films showed a polycrystalline anatase (004)-oriented phase without any second
phases. The optical band gap for undoped and doped films lay in the range 3.38 – 3.47 eV. Using dispersion
analysis, optical constants were determined from spectro-photometric measurements for films on glass.
Dye Sensitized Solar Cells Incorporated with Tio2 -ZnO NanoparticlesScientific Review SR
We demonstrated an improvement in efficiency of Dye sensitized solar cells (DSSCs) decorated with
zinc oxide (ZnO) nanoparticles (NPs) through successive ionic layer adsorption and reaction (SILAR). A series of
ZnO with different SILAR cycles were synthesized on TiO
2 that has been pre-grown on fluorine tin oxide (FTO)
glass slides. The performance of DSSCs containing ZnO NPs was significantly affected. The photovoltaic (PV)
performance decreased with increasing number of SILAR cycles from two SILAR cycles to four SILAR cycles,
the best performance was achieved using the anodes prepared with two SILAR cycles. The best cell shows a
conversion efficiency (η) of 0.0064 %. The cell exhibits ~ 2.13 improvement over the performance (0.0030 %) of
bare FTO-based device. The related PV performance enhancement mechanism is discussed
Synthesis, Characterization of ZnS nanoparticles by Coprecipitation method us...IOSR Journals
ZnS nanoparticles are prepared by coprecipitation method using various capping agents like PVP (polyvinylpyrrolidone), PVA (polyvinylalcohol) and PEG-4000 (polyethyleneglycol). These are characterized by UV-Visible spectra, X-ray diffraction (XRD) studies, Fourier Transform Infra-red spectra (FTIR) and Transmission electron microscopy (TEM). UV-Visible absorption spectra are used to find the optical band gap and the values obtained have been found to be in the range of 3.80-4.00eV. The particle size of nanoparticles calculated from XRD pattern has been in the range of 2-4 nm. It is also observed that the particle size of nanoparticle is affected by the nature of capping agent. Photo catalytic degradation of xylenol orange (XO) by the nanoparticles shows that these act as photo catalysts under sunlight irradiation. The XO dye was degraded more than 87.24, 83.42 and 73.05% in the presence of PEG-4000, PVA and PVP capped ZnS nanoparticles in 120, 150 and 180 min. respectively. The kinetics of catalyzed by synthesized ZnS nanoparticles with XO dye follows pseudo-first order kinetics with reasonable apparent rate constants.
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
Influence of Thickness on Electrical and Structural Properties of Zinc Oxide ...paperpublications3
Abstract: Zinc Oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 1500C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 〖34.31^0-34.35〗^0with hkl (002). Other parameters calculated include the stress ( ) and the grain size (D).
Surfactant-assisted Hydrothermal Synthesis of Ceria-Zirconia Nanostructured M...IOSR Journals
CeO2–ZrO2 oxides were prepared by the surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template and modified with chromium nitrate. These were characterized by XRD, FT-IR, TEM, SEM, BET and TPD-CO2. The XRD data showed that as prepared CeO2-ZrO2 powder particles have single phase cubic fluorite structure. HRTEM shows mesoscopic ordering. Average particle size is 12-13 nm as calculated from particle histogram. The nitrogen adsorption/desorption isotherm were classified to be type IV isotherm, typical of mesoporous material. The presence of uni-modal mesopores are confirmed by the pore size distribution which shows pore distribution at around 60 A°. Catalytic activity was studied towards liquid-phase oxidation of benzene.
Optical Characterization of Fluorine Doped Tin Oxide Deposited By Spray Pyrol...paperpublications3
Abstract: Fluorine doped tin oxide thin (FTO) films prepared by spray pyrolysis technique at a substrate temperature of 573K. The films deposited were 100 nm thick. After the deposition, the films were then annealed at different annealing temperatures of 423K, 573K and723K respectively in open air. The optical parameters of the prepared films as transmittance, optical energy gap, refractive index, extinction coefficient, porosity, packing density and the dielectric constants were found to be influenced by varying the annealing temperatures.
Keywords: FTO, annealing in open air, spray pyrolysis, porosity, packing density, dielectric constant.
Vapor Deposition of Semiconducting Phosphorus Allotropes into TiO2 Nanotube A...Pawan Kumar
Recent evidence of exponential environmental degradation will demand a drastic shift in research and development toward exploiting alternative energy resources such as solar energy. Here, we report the successful low-cost and easily accessible synthesis of hybrid semiconductor@TiO2 nanotube photocatalysts. In order to realize its maximum potential in harvesting photons in the visible-light range, TiO2 nanotubes have been loaded with earth-abundant, low-band-gap fibrous red and black phosphorus (P). Scanning electron microscopy– and scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron microscopy, and UV–vis measurements have been performed, substantiating the deposition of fibrous red and black P on top and inside the cavities of 100-μm-long electrochemically fabricated nanotubes. The nanotubular morphology of titania and a vapor-transport technique are utilized to form heterojunctions of P and TiO2. Compared to pristine anatase 3.2 eV TiO2 nanotubes, the creation of heterojunctions in the hybrid material resulted in 1.5–2.1 eV photoelectrocatalysts. An enhanced photoelectrochemical water-splitting performance under visible light compared with the individual components resulted for the P@TiO2 hybrids. This feature is due to synergistically improved charge separation in the heterojunction and more effective visible-light absorption. The electronic band structure and charge-carrier dynamics are investigated in detail using ultraviolet photoelectron spectroscopy and Kelvin probe force microscopy to elucidate the charge-separation mechanism. A Fermi-level alignment in P@TiO2 heterojunctions leads to a more reductive flat-band potential and a deeper valence band compared to pristine P and thus facilitates a better water-splitting performance. Our results demonstrate effective conversion efficiencies for the nanostructured hybrids, which may enable future applications in optoelectronic applications such as photodetectors, photovoltaics, photoelectrochemical catalysts, and sensors.
Vapor Deposition of Semiconducting Phosphorus Allotropes into TiO2 Nanotube A...
PAOT-3-FINAL(1)
1. Doped titania nanopowders with photocatalytic and antimicrobial
properties under visible light irradiation
D. S. Tsoukleris1, C. Psarras1, M. Loizidou2, E. Α. Pavlatou1, G. Chousos3, P.
Panagopoulos3, Ch. Vasilakos3, Th. Maggos3
1
.General Chemistry Laboratory, School of Chemical Engineering, National Technical
University of Athens
2
Unit of Environmental Science and Technology, School of Chemical Engineering,
National Technical University of Athens
9 Heroon Polytechniou Str., Zografos Campus, Athens GR-15780, Greece
3
Environmental Research Laboratory, INRASTES, NCSR “Demokritos”, Ag. Parskevi,
Athens, Greece
One of the most prevalent synthetic routes for the production of doped
nanostructured titania has become the so called sol-gel process, widely known as
hydrolysis-condensation (SOLution-GELation) which falls into the broad class of wet
chemistry methods. In this work emphasis has been given to the study of this specific
synthesis route, since it has become the most frequently applied synthetic method providing
various advantages.
In this study, titania nanopowder was prepared by sol–gel method using titanium
butoxide (TBOT) and distilled water/ HNO3 as titanium precursor and hydrolyzing agent,
respectively. An alcoholic solutions were added and the solution was stirred under vigorous
stirring. Then, added the dopant urea and stirred overnight. The prepared sol-gel solution
deposited onto glass spherules with spray pyrolysis method and calcinated to 450o
C in order
to be produced the final TiO2 thin film. X-ray diffraction patterns (XRD) of the calcinated
powders were obtained with a Siemens D5000 X-ray diffractometer in the diffraction angle
range 2θ = 20o
-80o
using Cu Kα radiation. FT-Infrared spectra were obtained on a Jasco
4200 spectrophotometer and the spectra were recorded for a wave number range from 700 to
5000 cm-1
with a resolution of 8 cm-1
by using the ATR method. Diffuse reflectance UV-
Vis spectra from 200nm to 700nm with slit width of a few nm was collected on a Hitachi
3010 spectrophotometer. Moreover, morphology and particle size were studied by using
electron microscopy (SEM).
In order to enhance the efficiency of TiO2 under visible irradiation, the produced
nanomaterial was modified with non-metal dopants aimed to decrease the band gap that
facilitates visible light absorption. In terms of the use of TiO2 in semiconductors, band gap
was arguably one of the most important properties. In general, the band gap of the TiO2
nano-particles is from 3.0 to 3.2eV whereas in this study the band-gap was estimated to be
below 2.5 eV by the reflectance UV-Vis spectra. The XRD data demonstrate that all
powders could be characterized as nanocrystalline as well as the FEG-SEM results (Fig. 1).
The photocatalytic efficiency of the material was evaluated in a photoreactor by the
photo-degradation of benzene, toluene and o-, m-, p-, xylenes and ethylbenzene (BTEX).
0.03 m2
of the powder (spherules) were placed inside a pyrex (permitting radiation pass
when wavelength is over 320 nm) glass tube (50 cm in length and 1.5 cm in diameter),
which in turn was incorporated in the central axis of the photoreactor. A known
concentration of VOCs (approx. 20 ppb/v) with 0.2m3
/h flow rate passed from the glass
tube, while the 4 Vis-lamps were irradiating the system. The analysis of VOCs
concentration was conducted by an automated GC-PID (955 Syntec Spectras) providing
2. VOCs concentrations every 15 minutes interval. Preliminary results shown significant
degradation of xylenes and ethyl-benzene (70% and 60% respectively) while the
corresponding value for toluene was quite lower (7.44%).Accordingly the photocatalytic
rate (μg/m2
s) was calculated 0.03, 0.01 and 0.002 for xylene and ethyl-benzene and toluene
respectively.
Figure 1. SEM image of synthesized TiO2 nano-powders