Study the effect of Mn2+ ions on the ac electrical properties of some iron do...IJRES Journal
Oxide glasses doped with transition metal ions are of high interest because of their variant applications in both science and technology fields. However, the normal melt quench method have used to prepared some iron doped phosphate glasses according the following molecular formula: (65-x) mol% P2O5 - 20 mol% Na2O - 15 mol% Fe2O3 - x mol% MnO, Where x= 0, 5,10, 20, 25. The room temperature Mössbauer Effect ME Spectra used to characterized the glassy state homogeneity of these glasses. ME spectra show, for all glasses, no magnetic field participate which mean good glassy state formation. The ac electrical transport properties were also measured, as function of temperature up to 500k. It was found that the ac conductivity increased with the gradual increase of Mn2+ cations, while the electrical activation energy decreased.
Direct Synthesis Carbon/Metal Oxide Composites for Electrochemical Capacitors...drboon
This paper deals with the study of the carbon/metal oxide composites synthesis for electrochemical capacitor electrode material. Transition metal salts, such as FeCl3 and TiCl3 act as activator in the synthesis of activated carbon from gelam wood sawdust (Melaleuca cajuputi Powell) which also have the functions as substrates for the composites. The surface functionalities of activated carbons were modified using oxidative treatments. The changes on crystallography and surface functionalities were analyzed based on XRD and FTIR data. The electrical conductivities and electrochemical properties were determined using kelvin and cyclic voltammetry methods, respectively. FTIR analyses showed that the activation and oxidation treatments affected their surface functionalities. The XRD analyses showed that oxidative treatments also affected carbons crystallite. The electrical conductivities and electrochemical properties were influenced by their crystallite and surface functionalities. The shape of the cyclic voltammograms varied according to the changes on the surface functionalities and on the metals loading. TEM analyses indicated the existence of nanoparticles metal oxides in the carbon samples.
Study the effect of Mn2+ ions on the ac electrical properties of some iron do...IJRES Journal
Oxide glasses doped with transition metal ions are of high interest because of their variant applications in both science and technology fields. However, the normal melt quench method have used to prepared some iron doped phosphate glasses according the following molecular formula: (65-x) mol% P2O5 - 20 mol% Na2O - 15 mol% Fe2O3 - x mol% MnO, Where x= 0, 5,10, 20, 25. The room temperature Mössbauer Effect ME Spectra used to characterized the glassy state homogeneity of these glasses. ME spectra show, for all glasses, no magnetic field participate which mean good glassy state formation. The ac electrical transport properties were also measured, as function of temperature up to 500k. It was found that the ac conductivity increased with the gradual increase of Mn2+ cations, while the electrical activation energy decreased.
Direct Synthesis Carbon/Metal Oxide Composites for Electrochemical Capacitors...drboon
This paper deals with the study of the carbon/metal oxide composites synthesis for electrochemical capacitor electrode material. Transition metal salts, such as FeCl3 and TiCl3 act as activator in the synthesis of activated carbon from gelam wood sawdust (Melaleuca cajuputi Powell) which also have the functions as substrates for the composites. The surface functionalities of activated carbons were modified using oxidative treatments. The changes on crystallography and surface functionalities were analyzed based on XRD and FTIR data. The electrical conductivities and electrochemical properties were determined using kelvin and cyclic voltammetry methods, respectively. FTIR analyses showed that the activation and oxidation treatments affected their surface functionalities. The XRD analyses showed that oxidative treatments also affected carbons crystallite. The electrical conductivities and electrochemical properties were influenced by their crystallite and surface functionalities. The shape of the cyclic voltammograms varied according to the changes on the surface functionalities and on the metals loading. TEM analyses indicated the existence of nanoparticles metal oxides in the carbon samples.
IrO2 as an anodic electrocatalyst for the oxygen evolution reaction (OER) in solid polymer electrolyte (SPE)
electrolysers was synthesised by adapting the Adams fusion method. Optimisation of the IrO2 electrocatalyst was achieved
by varying the synthesis duration (0.5 – 4 hours) and temperature (250 - 500°C). The physical properties of the
electrocatalysts were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and
x-ray diffraction (XRD). Electrochemical characterisation of the electrocatalysts toward the OER was evaluated by
chronoamperometry (CA). CA analysis revealed the best electrocatalytic activity towards the OER for IrO2 synthesised
for 2 hours at 350oC which displayed a better electrocatalytic activity than the commercial IrO2 electrocatalyst used in this
study. XRD and TEM analyses revealed an increase in crystallinity and average particle size with increasing synthesis
duration and temperature which accounted for the decreasing electrocatalytic activity. At 250°C the formation of an active
IrO2 electrocatalyst was not favoured.
A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitr...CrimsonPublishersRDMS
A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitrogen by Majid Monajjemi* in Crimson Publishers: Peer Reviewed Material Science Journals
Hydrothermal Assisted Microwave Pyrolysis of Water Hyacinth for Electrochemic...drboon
We develop ‘green’ approach to prepare conductive carbon material from water hyacinth (Eichhornia crassipes) powder for use in electrochemical capacitor device. The features on morphology, crystallography and surface functionality were analyzed based on SEM, XRD and FTIR instrumentation, respectively. The electrical conductivities were measured using four-point probe. Electrochemical properties were studied using cyclic voltammetry. SEM analyses indicated the existence of nanoparticles in the carbon samples. XRD analysis showed that carbon sample had sharp peaks indicating crystallite carbon and sylvite. FTIR analysis showed that the carbon have common surface functionalities which also can be found in other conductive carbon samples. The electrical conductivities test showed that the carbon had 0.001–1.5 S cm-1 of conductivity. The shape of the cyclic voltammograms were typical for carbon electrode that use in electrochemical capacitor.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
IrO2 as an anodic electrocatalyst for the oxygen evolution reaction (OER) in solid polymer electrolyte (SPE)
electrolysers was synthesised by adapting the Adams fusion method. Optimisation of the IrO2 electrocatalyst was achieved
by varying the synthesis duration (0.5 – 4 hours) and temperature (250 - 500°C). The physical properties of the
electrocatalysts were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and
x-ray diffraction (XRD). Electrochemical characterisation of the electrocatalysts toward the OER was evaluated by
chronoamperometry (CA). CA analysis revealed the best electrocatalytic activity towards the OER for IrO2 synthesised
for 2 hours at 350oC which displayed a better electrocatalytic activity than the commercial IrO2 electrocatalyst used in this
study. XRD and TEM analyses revealed an increase in crystallinity and average particle size with increasing synthesis
duration and temperature which accounted for the decreasing electrocatalytic activity. At 250°C the formation of an active
IrO2 electrocatalyst was not favoured.
A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitr...CrimsonPublishersRDMS
A Nano Capacitor Including Graphene Layers Composed with Doped Boron and Nitrogen by Majid Monajjemi* in Crimson Publishers: Peer Reviewed Material Science Journals
Hydrothermal Assisted Microwave Pyrolysis of Water Hyacinth for Electrochemic...drboon
We develop ‘green’ approach to prepare conductive carbon material from water hyacinth (Eichhornia crassipes) powder for use in electrochemical capacitor device. The features on morphology, crystallography and surface functionality were analyzed based on SEM, XRD and FTIR instrumentation, respectively. The electrical conductivities were measured using four-point probe. Electrochemical properties were studied using cyclic voltammetry. SEM analyses indicated the existence of nanoparticles in the carbon samples. XRD analysis showed that carbon sample had sharp peaks indicating crystallite carbon and sylvite. FTIR analysis showed that the carbon have common surface functionalities which also can be found in other conductive carbon samples. The electrical conductivities test showed that the carbon had 0.001–1.5 S cm-1 of conductivity. The shape of the cyclic voltammograms were typical for carbon electrode that use in electrochemical capacitor.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Photoelectrochemical characterization of titania photoanodes fabricated using...Arkansas State University
Design and fabrication of new electrodes for photo-electrolysis using a material that is photo-active, stable, corrosion resistant, and cost effective.
Electrochemical Degradation of Methylen Blue Using Carbon Composite Electrode...iosrjce
Electrochemical oxidation of methylene blue using carbon composite electrode in sodium chloride
solution have been done. The aim of this work was to degradation of methylen blue using the direct oxidation in
undivided electrolysis cell. Carbon composite electrode was prepare by C powder and PVC in 4 mL
tetrahydrofuran (THF) solvent and swirled flatly to homogeneous followed by drying in an oven at 100 °C for 3
h. The mixture was placed in stainless steel mould and pressed at 10 ton/cm2
. Sodium chloride was used
electrolyte solution. The effects of the current and electrolysis time were investigated using cyclic voltammetry,
spectrophotometer UV-Visible and gas chromatography mass spectrometry (GC-MS). The experimental results
showed that the carbon composite electrode have higher effect in the electrochemical degradation of methylene
blue. Based on UV-visible spectra and GC-MS analysis also shows current and electrolysis time for
degradation of methylene blue optimum at 1,5 A and 60 minute, respectively. As a conclusions is this method its
simple equipment, easy operation and friendly for environmental.
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of Temperature and Nickel Concentration on the Electrical and Dielectr...IJERD Editor
In this paper the effect of temperature range of 298 K to 348 K and volume filler content ф on
electrical properties of polyethylene PE filled with nickel Ni powders has been investigated .The volume
electrical resistivity
V
of such composites decreases suddenly by several orders of magnitude at a critical
volume concentration (i.e. фc=14.27 Vol.%) ,whereas the dielectric constant and the A.C electrical
conductivity AC of such composites increase suddenly at a critical volume concentration (i.e. фc=14.27
Vol.%).For volume filler content lower than percolation threshold ф<фc> фc there is increase in the value of their
resistivity, and decrease in the value of their dielectric constant and the A.C electrical conductivity AC with
increasing temperature indicating metallic-conduction.
Performance of carbon nanofiber supported pd–ni catalysts for electro oxidati...suresh899
Carbon nanofibers (CNF) supported Pd–Ni nanoparticles have been prepared by chemical reduction
with NaBH4 as a reducing agent. The Pd–Ni/CNF catalysts were characterized by X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical
voltammetry analysis. TEM showed that the Pd–Ni particles were quite uniformly distributed on the
surface of the carbon nanofiber with an average particle size of 4.0 nm. The electro-catalytic activity of
the Pd–Ni/CNF for oxidation of ethanol was examined by cyclic voltammetry (CV). The onset potential
was 200mV lower and the peak current density four times higher for ethanol oxidation for Pd–Ni/CNF
compared to that for Pd/C. The effect of an increase in temperature from 20 to 60 ◦C had a great effect on
increasing the ethanol oxidation activity.
Performance of carbon nanofiber supported pd–ni catalysts for electro oxidati...sunilove
Carbon nanofibers (CNF) supported Pd–Ni nanoparticles have been prepared by chemical reduction
with NaBH4 as a reducing agent. The Pd–Ni/CNF catalysts were characterized by X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical
voltammetry analysis. TEM showed that the Pd–Ni particles were quite uniformly distributed on the
surface of the carbon nanofiber with an average particle size of 4.0 nm. The electro-catalytic activity of
the Pd–Ni/CNF for oxidation of ethanol was examined by cyclic voltammetry (CV). The onset potential
was 200mV lower and the peak current density four times higher for ethanol oxidation for Pd–Ni/CNF
compared to that for Pd/C. The effect of an increase in temperature from 20 to 60 ◦C had a great effect on
increasing the ethanol oxidation activity.
Corrosion Inhibition of Mild Steel in HCl Medium by a Condensation Productijtsrd
A condensation product CP was successfully synthesized from reaction of dimethyl amino benzaldehyde and aniline giving yields of 80 . The compound was characterized by Fourier Transform Infrared FTIR Spectroscopy. The corrosion inhibiting property of the CP on mild steel in HCl solution were investigated by the weight loss measurements, electrochemical impedance spectroscopy EIS and linear polarization resistance LPR . The concentrations of CP were varied from 1 x 10 3 M to 5 x 10 3 M. The inhibition efficiencies obtained from all the methods employed were in good agreement where the percentage of inhibition efficiencies increased with concentration of CP. Results showed that CP was the better inhibitor with inhibition efficiency of 90 at 5 x 10 3 M additive concentration. This is likely due to the effect of its large molecular size, higher number of electroactive heteroatoms and bigger p electron cloud of the conjugated double bond system. Ganesha Achary "Corrosion Inhibition of Mild Steel in HCl Medium by a Condensation Product" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30869.pdf Paper Url :https://www.ijtsrd.com/chemistry/physical-chemistry/30869/corrosion-inhibition-of-mild-steel-in-hcl-medium-by-a-condensation-product/ganesha-achary
Maiyalagan,Performance of carbon nanofiber supported pd ni catalysts for elec...kutty79
Carbon nanofibers (CNF) supported Pd–Ni nanoparticles have been prepared by chemical reduction
with NaBH4 as a reducing agent. The Pd–Ni/CNF catalysts were characterized by X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical
voltammetry analysis. TEM showed that the Pd–Ni particles were quite uniformly distributed on the
surface of the carbon nanofiber with an average particle size of 4.0 nm. The electro-catalytic activity of
the Pd–Ni/CNF for oxidation of ethanol was examined by cyclic voltammetry (CV). The onset potential
was 200mV lower and the peak current density four times higher for ethanol oxidation for Pd–Ni/CNF
compared to that for Pd/C. The effect of an increase in temperature from 20 to 60 ◦C had a great effect on
increasing the ethanol oxidation activity
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Unveiling the Energy Potential of Marshmallow Deposits.pdf
J0436469
1. IOSR Journal of Applied Chemistry (IOSR-JAC)
e-ISSN: 2278-5736.Volume 4, Issue 3 (May. – Jun. 2013), PP 64-69
www.iosrjournals.org
www.iosrjournals.org 64 | Page
Design and Application of Cu, Co, Ni, Pt and Ir Powder
Composite Electrode (PCE) For Electrosynthesis and
Electroanalysis in Alkaline Solution
Riyantoa
a
Chemistry Study Program, Faculty of Mathematic and Natural Science
Islamic University of Indonesia Jl. Kaliurang KM 14.5 Yogyakarta 55584
Abstract: Design and application of powder composite electrodes for electrosynthesis and electroanalysis
research has been carried out. The physical characterization of electrodes was analysis using SEM, EDX and
FTIR. The electrochemical stability was analysis using cyclic voltammetry. The stability of electrodes was
analyzed using Atomic Absorption Spectroscopy (AAS). The powder composite electrodes were prepared by
mixing 95% metal powder with 5% polyvinyl chloride (PVC). PVC was used as a binder and tetrahydrofuran
(THF) was used as a mixing solvent in powder composite electrodes preparation. The result, of the study
showed powder composite electrode higher stability compared to metal sheet electrode. Electrooxidation of
ethanol in KOH solution powder composite electrodes has shown good stability based on analysis using AAS.
The composite electrode has shown higher current density, so that we use for electrochemistry research such
electrosynthesis, electroanalysis and electrodegradations.
Keywords: Electrochemical stability, Composite Electrode, Ethanol, KOH
I. Introduction
Electrocatalytic activity of copper and nickel materials strongly depends on their morphology, surface
area and structure, composition, which in turn depend on the preparation methods [1]. These metals, being
transition elements, with their electronic layer d incomplete, have shown good electrocatalytic properties for the
oxygen reduction reaction (ORR). Recently, there have been proposals of copper combined with Pd, Ag, Ni or
Au for the ORR. The mechanical alloying technique to prepare cobalt–nickel alloys and to evaluate their
performance for the oxygen reduction reaction in alkaline media has been carried out [2]. The higher current
density associated to the cobalt–nickel an alloy was attributed to a synergistic effect for the electrocatalytic
activity.
The filling of a polymer with metallic particles results in an increase of both electrical and thermal
conductivity of the composite obtained. The influence of the type of polymer matrix and filler on the electrical
characteristics of the composite has been studied in many works [3]. One of the techniques of making the porous
electrode is by incorporating polymer material like polyvinyl chloride (PVC) with the powder of respected
metals [3-8].
Powders of nickel and copper are widely used in numerous applications because they possess good
catalytic, electronic and magnetic properties [9]. Ni powder, for example, has been used in catalysis for the
direct cracking of methane whereas CeO2 supported copper catalysts has been tested for NO reduction. The
influences of aggregation on the magnetic properties of Ni nano particles synthesized by hydrogen reduction and
the magneto-resistance of Ni-based thick films have also been investigated. Nickel and copper powders are
extensively used as the active anode material in solid oxide fuel cells.
Electrode in electrosynthesis is truly fundamental. According to Couper et al. (1990), some general
guidelines to assit the choice of an electrode materil are physical stability, chemical stability, suitable physisc
form, rate and product selectivity, electrical conductivity and cost (lifetime) [10]. The need for a suitable
combination of mechanical, physical, and chemical stability has already been stressed. It is important to
recognize that the stability must be maintained under all conditions met be the electrode material. Besides
chemical and electrochemical stability, electrode are chosen for industrial use to be relatively inexpensive,
highly conducting and electrocatalytic. An electrocatalytic electrode is one which exhibits a low overvoltage for
a given process. In addition, electrocatalysis implies high product selectivity especially importance in the
electrosynthesis of organic compounds.
The present paper aims to discribe the electrochemical stability of Cu, Ni, Co, Pt, Ir powder composite
electrodes for electrooxidation of ethanol in KOH solution. The electrochemical stability was analysis using
cyclic voltammetry. Cyclic voltammetry very suitable for the study of electrochemical stability [11].
2. Design And Application Of Cu, Co, Ni, Pt And Ir Powder
www.iosrjournals.org 65 | Page
II. Experiments
Solutions
All solutions were prepared by dissolving their analytical grade reagent (Merck) in deionised distilled
water. KOH was used as the supporting electrolyte. Nitrogen was used to deaerate the solutions and to keep an
inert atmosphere over the reaction solution during the oxidation process. Ethanol solutions were prepared by
dilution of absolute ethanol (BDH laboratory supplies) with deionised distilled water.
Preparation of Composite Electrode
The composite electrode was prepared by mixing a weighed portion of metal powder (< 2 micron in
size and 99.9% purity, Aldrich Chemical Company) and PVC in 4 ml tetrahydrofuran (THF) solvent and swirled
flatly to homogeneous followed by drying in an oven at 1000
C for 3 hours. The mixture was placed in 1 cm
diameter stainless steel mould and pressed at 10 ton/cm2
. A typical pellet contained approximately 95% of metal
powder and 5% of PVC polymer. The total weighed of pellet obtained is approximately 1.5 g. The same
treatments as solid metal foil were later carried out for composite electrode preparation.
Electrochemical Stability of The Electrodes
Universal Pulsa Dynamic EIS, Voltammetry, Voltalab potentiostat (Model PGZ 402) was used for
electrochemical stability measurements, data acquisition was accomplished using the Voltamaster 4 software.
Cyclic voltammetry experiments were performed in a three electrodes system using composite electrode (Cu-
PVC, Ni-PVC, Co-PVC, Pt-PVC and Ir-PVC) as a working electrode (anode), SCE as reference electrode and
platinum wire as the counter electrode. All potentials given are with respect to the SCE reference electrode.
Chemical Stability of The Electrodes
The electrolysis process of ethanol was performed in a solution of 1.0 M KOH at room temperature.
The electrochemical stability by cyclic voltammetry (CV) and oxidation of ethanol by potentiostatic
(chronocoulometry) method were performed in 25 mL capacity glass electrochemical cell. Chemical stability of
the electrode was analyzed using Atomic Absorption Spectroscopy (AAS).
III. Result And Discussion
SEM micrograph at Fig. 1A shown in electrodes surface were very rough, irregular and having porous
characteristic. It has been reported that electrode prepared using powdered metal-PVC yielded electrode have
surface which is very rough, irregular, and formed a lamellar orientated particles. The picture shown in Fig. 1B
and IC indicates that the surface and cross section morphology is highly heterogeneous and composed of
aggregates of nickel particles separated by gaps of PVC and voids between aggregate of nickel. Analysis on Ni-
PVC electrode using EDS showed the existence of Ni, C and of Cl peaks (Fig.1D). The existing C and Cl peaks
show the existence of PVC on the surface of the electrode. The bonding between PVC and metal occurred
through Cl atom from PVC and metal to form Ni-Cl bonding, which produced a good strength electrode.
Fig. 1 Electrode Ni-PVC from surface (A) SEM micrograph at surface (B) and
cross section (C) with magnification x 1000, and EDS spectra (D).
A B
C D
3. Design And Application Of Cu, Co, Ni, Pt And Ir Powder
www.iosrjournals.org 66 | Page
Fig. 2 showed FTIR spectra of THF+PVC (A) and Cu-PVC electrode. Wavelength number at 1036.75
cm-1
showed C-O bonding, while 2964.46 cm-1
showed C-H bonding. The effect of heated at 100o
C showed new
peak at wavelengths number 2360.41 cm-1
and loss of peak at 2360.41 and 3438.28 cm-1
.
Fig. 2. FTIR spectra of THF+PVC (A) and Cu-PVC electrode (B)
Cyclic Voltammetry of Composite Electrodes
Fig. 3 (A and B) shows the cyclic voltammogram of 1.0 M KOH with the sweep potential from
potential -700 up to +700 mV, and then return from +700 mV up to -700 mV using Cu-PVC electrode. The A1,
A2, A3 and A4 peaks represent the anodic peaks. These peaks related to the oxidation of Cu(0) to Cu(I), Cu(I)
to Cu(II) and Cu(II) to Cu(III). The C1 peak in shows the reduction process of Cu(III) to Cu(II) whiles the C2
peak shown the reduction of Cu(II) to Cu(I) or Cu(0) . Fig. 3A and 3B show the cyclic voltammograms of Cu
metal foil with one cycle and four cycles (continues cycle), respectively, where the same anodic peaks were
recorded for both process. The only significant difference between the cyclic voltammograms of Fig. 3A and 3B
are degradation of current density. For four cycle higher current density was observed at first cycle, and then
increase for second, third and fourth cycle. Because Cu electrode not stability in 1.0 M KOH. Cu metal is easily
oxidized to form oxide compounds in the alkaline medium, which would formed oxide coating on the surface of
the electrode, Cu2O, CuO, and Cu(OH)2, besides the other species depending on the potential, pH of the
solution, the mass-transport conditions, ageing and surface restructuring processes [12].
Fig. 3 C, E, G and I shows cyclic voltammograms using Ni, Co, Pt and Ir composite electrode in 1.0 M
KOH (Ni and Co electrode) and in 0.25 M ethanol + 1.0 M KOH (Pt and Ir electrode). Fig. 3 D, F, H and J
shows cyclic voltammograms the effect of continues cycling using Ni, Co, Pt and Ir composite electrode in 1.0
M KOH (Ni and Co electrode) and in 0.25 M ethanol + 1.0 M KOH (Pt and Ir electrode).
Fig. 3 A, C, E, G and I shows cyclic voltammograms using Ni, Co, Pt and Ir composite electrode in 1.0
M KOH (Cu-PVC, Ni-PVC and Co-PVC composite electrodes) and in 0.25 M ethanol + 1.0 M KOH (Pt-PVC
and Ir-PVC composite electrodes). Fig. 3 B, D, F, H and J shows cyclic voltammograms the effect of continues
cycling using Cu-PVC, Ni-PVC, Co-PVC, Pt-PVC and Ir-PVC composite electrode in 1.0 M KOH (Ni and Co
composite electrode) and in 0.25 M ethanol + 1.0 M KOH (Pt and Ir composite electrode). Fig. 3 D, F, H and J
shows Ni-PVC, Co-PVC, Pt-PVC and Ir-PVC composite electrodes good stability for electrochemical oxidation
in KOH solution.
-800 -600 -400 -200 0 200 400 600 800
-60
-40
-20
0
20
40
60
80
100
120
140
C1
A4
A3
A2
A1
Currentdensity[mA/cm²]
Potential [mV]
-1.0 -0.5 0.0 0.5 1.0
-60
-40
-20
0
20
40
60
80
100
cycle 1
Currentdensity[mA/cm²]
Potential [V]
cycle 5
A B
A
B
4. Design And Application Of Cu, Co, Ni, Pt And Ir Powder
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0 100 200 300 400 500
-10
-5
0
5
10
15
C1
A1
Currentdensity[mA/cm²]
Potential [mV]
0 100 200 300 400 500
-40
-30
-20
-10
0
10
20
30
40
cycle 10
cycle 1
Currentdensity[mA/cm²]
Potential [mV]
-400 -200 0 200 400 600
-10
0
10
20
30
40
50
60
70
C2 C1
A2
A1
Currentdensity[mA/cm²]
Potential [mV]
-400 -200 0 200 400 600
-20
-10
0
10
20
30
40
50
60
70
80
90
Currentdensity[mA/cm²] Potential [mV]
cycle 1
cycle 5
-800 -600 -400 -200 0 200 400 600 800 1000
-50
0
50
100
150
200
C1
A2
A1
Currentdensity[mA/cm²]
Potential [mV]
-800 -600 -400 -200 0 200 400 600 800 1000
-100
-50
0
50
100
150
200
250
cycle 5
C1
A2
A1
cycle 1
Currentdensity[mA/cm²]
Potential [mV]
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
-30
-20
-10
0
10
20
30
C1
A2
A1
Currentdensity[mA/cm²]
Potential [V]
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
-30
-20
-10
0
10
20
30
cycle 5
cycle 1
Currentdensity[mA/cm²]
Potential [V]
Fig. 3. Cyclic voltammograms (A, C, E, G, I) Cu, Ni, Co, Pt, Ir composite electrodes with one cycle, and
(B, D, F, H, J) for Cu, Ni, Co, Pt, Ir composite electrodes with continues cycle at 5 cycle for Cu-PVC, 5
cycle for Co-PVC, Pt-PVC, Ir-PVC and 10 cycle for Ni-PVC, in 1.0 M KOH. Cyclic voltammograms Pt-
PVC and Ir-PVC electrodes in 0.25 M ethanol + 1.0 M KOH. Scan rate of Cu-PVC: 10; Ni-PVC:30; Co-
PVC: 10; Pt-PVC; 20 and Ir-PVC; 50 mV/sec
Table 1 shows electrochemical activity and stability parameters for composite electrodes in 1.0 M
KOH. The result from the cyclic voltammetry showed that the electrochemical activity and stability in alkaline
solution using composite electrode is at a higher current density. This indicates that composite electrode gave a
better electrochemical activity and stability for the electrochemical oxidation in KOH compared to solid
electrode. The higher current density showed higher electrochemical activity [2]. From these cyclic voltammetry
C D
E F
G H
I J
5. Design And Application Of Cu, Co, Ni, Pt And Ir Powder
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experiments, the composite electrodes are suitable for electrosynthesis and fuel cell. Composite electrodes are
more economical and beneficial for the oxidation of materials compared to solid metal electrode due to higher
current density; hence more oxidation process will occur.
Table 1. Data of activity and stability of composite electrodes
Composite
electrodes
Maximum current density
(mA/cm2
)
Activity Stability
Cu-PVC 130.2 Large activity No stability
Ni-PVC 12.5 Medium activity Good stability
Co-PVC 45.3 Medium activity Good stability
Pt-PVC 82.1 Large activity Good stability
Ir-PVC 28.4 Medium activity Good stability
Chemical Stability of Electrodes
The stability of electrode was analyzed using Atomic Absorption Spectroscopy (AAS). Analyzed have
been done at three shares are solution, sponge formed on the electrode surface of anode and cathode. Table 2
shows metal concentration in solution and electrode surface (anode and cathode) or sponge, result of electrolysis
0.25 M ethanol by solid electrode, electrolysis time 6 h at potential constant 1050 mV, analyzed using AAS.
Table 2 shows that Co, Ni and Cu electrodes the higher corrosion compared the Pt and Ir metal
electrode in alkaline solution. Ni metal electrode experience of the biggest corrosion at 0.1 and 1.0 M KOH. Co
electrode at concentration 0.1 M KOH on the electrode surface formed sponge the higher concentration
compared Ni and Cu electrode. Electrochemical oxidation of ethanol in 0.1 M KOH formed sponge on electrode
surface with quantity of Co, Ni and Cu are 79.7 mg, 71.25 and 19.150 mg, respectively. If weight from the
beginning Co electrode is 856.7 mg, hence a period of electrolysis 6 h, Co electrode formed sponge reach
9.32%. Sponge of a lot of formed on the electrode surface, if electrolysis ethanol in 0.1 M KOH. Electrolysis
ethanol in 1.0 M KOH on electrode surface happened of the degradation sum up the sponge. Electrolysis ethanol
in 1.0 M KOH using Cu electrode not formed sponge in anode surface, while in cathode a lot of formed of
sponge.
Table 2 shows result of analysis chemical stability of composite electrode after used for the electrolysis
of 0.25 M ethanol in 1.0 and 0.1 M KOH with electrolysis time 6 h at 1050 mV. In generally, metal content in
solution very low for all composite electrodes. Although however, the forming of sponge on the electrode
surface Co-PVC, Ni-PVC and Cu-PVC cause the corrosion also go into effect at composite electrode. Sponge a
lot of formed at electrolysis ethanol in 0.1 M KOH especially at electrode surface of Co-PVC, Ni-PVC and Cu-
PVC. Composite electrodes have the good stability in alkali solution. He is shown by lowering dissolve metal
concentration during electrolysis.
Table 2. Metal concentration in solution and electrode surface (anode and cathode) or sponge, result of
electrolysis 0.25 M ethanol by composite electrode, electrolysis time 6 h at potential constant 1050 mV,
analyzed to use AAS
Type electrodes
KOH (M)
Metal concentration (mg) in
Solution Electrode surface
(anode)
Electrode surface
cathode (Pt)
Co-PVC 0.1 0.982 49.700 0.486
1.0 0.671 7.236 7.240
Cu-PVC 0.1 0.874 23.150 2.341
1.0 0.562 - 17.591
Ni-PVC 0.1 3.775 65.452 -
1.0 2.583 11.392 -
Pt-PVC 0.1 0.008 - -
1.0 0.023 - -
Ir-PVC 0.1 0.000 - -
1.0 0.000 - -
Note: (-) not formed sponge
6. Design And Application Of Cu, Co, Ni, Pt And Ir Powder
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IV. Conclusions
Ni, Co, Ir and Pt composite electrode higher stability compared to Cu composite electrode. Electrooxidation of
ethanol in KOH solution using composite electrodes has shown good stability based on analysis using AAS. The
composite electrode has shown higher current density in KOH solution.
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