scholarly journals Surfactant-free synthesis of carbon-supported silver (Ag/C) nanobars as an efficient electrocatalyst for alcohol tolerance and oxidation of sodium borohydride in alkaline medium

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Santanu Dey ◽  
Pradipta Chakraborty ◽  
Dhiraj Kumar Rana ◽  
Subhamay Pramanik ◽  
Soumen Basu
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Alkaline Medium ◽  
Sodium Borohydride ◽  
Metallic Silver ◽  
Alcohol Tolerance ◽  
Current Ratio ◽  
X Ray ◽  
Scan Rate ◽  
Borohydride Oxidation

AbstractWe have synthesized carbon-supported silver (Ag/C) nanobars by a simple surfactant-free hydrothermal method using glucose as the reducing reagent as well as the source of carbon in Ag/C nanobars. Physicochemical characterization of the materials was performed by X-ray Diffraction (XRD), field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The XRD pattern confirmed the presence of a pure metallic silver phase. No carbon phase was detected, which indicates that the carbon exists mainly in the amorphous form. The electrocatalytic activity of Ag/C in different electrolyte solutions such as 0.5 M NaOH, 0.5 M NaOH + 1 M ethanol (EtOH), 0.5 M NaOH + 1 M ethylene glycol (EG), and 0.5 M NaOH + 0.01 M NaBH4 (sodium borohydride) was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) study. Alcohol tolerance of the catalysts was also established in the presence of ethanol and ethylene glycol. The forward-to-backward current ratio from cyclic voltammetry (CV) study of Ag/C-20 (20 h) in 0.5 M NaOH + 1 M ethanol solution at 100 mV s−1 scan rate is 4.13 times higher compared to that of Ag/C-5 (5 h). Hence, Ag/C-20 is a better candidate for the tolerance of ethanol. In the presence of ethylene glycol (1 M) in 0.5 M NaOH solution, it is obtained that the forward-to-backward current ratio at the same scan rate for Ag/C-20 is lower than that in the presence of ethanol. The durability of the catalyst was studied by chronoamperometry measurement. We studied the electrochemical kinetics of Ag/C catalysts for borohydride oxidation in an alkaline medium. The basic electrochemical results for borohydride oxidation show that Ag/C has very well strength and activity for direct borohydride oxidation in an alkaline medium. The reaction of borohydride oxidation with the contemporaneous BH4−. hydrolysis was noticed at the oxidized silver surface. Among all the synthesized Ag/C catalysts, Ag/C-20 exhibited the best electrocatalytic performance for borohydride oxidation in an alkaline medium. The activation energy and the number of exchange electrons at Ag/C-20 electrode surface for borohydride electro-oxidation were estimated as 57.2 kJ mol−1 and 2.27, respectively.

scholarly journals Comparative Study of Ag Nanostructures: Molecular Simulations, Electrochemical Behavior, and Antibacterial Effect

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Álvaro de Jesús Ruíz-Baltazar ◽  
Simón Yobanny Reyes-López ◽  
D. Larrañaga ◽  
R. Pérez
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Comparative Study ◽  
Sodium Borohydride ◽  
Electrochemical Behavior ◽  
Antibacterial Effect ◽  
Chemical Reduction ◽  
Molecular Simulations ◽  
The Other ◽  
E Coli

Nanoparticles of Ag with different sizes and structures were obtained and studied. Two methods for reductions of Ag ions were employed, chemical reduction by sodium borohydride and ethylene glycol. Cuboctahedral and icosahedral structures were obtained. Molecular simulations were carried out in order to evaluate the reactivity of both structures. On the other hand, the electrochemical activity and antibacterial effect (E. coli) of the cuboctahedral and icosahedral structures were measured experimentally. The results obtained by molecular simulation, cyclic voltammetry, and antibacterial effect were compared and discussed in this work.

Electrochemical performance of M3(BTC)2·12H2O (M=Co, Ni, and Zn) for Supercapacitors

2011 ◽  
Vol 15 (2) ◽  
pp. 79-82
Author(s):  
Chenmin Liao ◽  
Jiachang Zhao ◽  
Bohejin Tang ◽  
Aomin Tang ◽  
Yanhong Sun ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scan Rate ◽  
Metal Organic ◽  
Acetate Hydrate ◽  
Xrd Patterns ◽  
Maximum Specific Capacitance

A series of Metal-Organic Frameworks (MOFs) based on 1,3,5-benzenetricarboxylic (BTC) acid and M(II) acetate hydrate (M=Co, Ni, and Zn) were successfully synthesized and named as M3(BTC)2·12H2O. These compounds were examined by X-ray diffraction (XRD) patterns. Electrochemical properties of the materials were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 6 M KOH aqueous solutions. The maximum specific capacitance of Ni3(BTC)2·12H2O is found to be 429 F g-1 at 5 mV s-1 and 154 F g-1 at 200 mV s-1 scan rate.

scholarly journals Platinum Nanoparticles Modified Copper/Titanium Electrodes as Electrocatalysts for Borohydride Oxidation

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7663
Author(s):  
Aldona Balčiūnaitė ◽  
Aušrinė Zabielaitė ◽  
Daina Upskuvienė ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Irena Stalnionienė ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Sodium Borohydride ◽  
Platinum Nanoparticles ◽  
Icp Oes ◽  
Galvanic Displacement ◽  
Electroless Copper Plating ◽  
Titanium Catalysts ◽  
Electroless Copper ◽  
Borohydride Oxidation ◽  
Composition Structure

In this study, sodium borohydride oxidation has been investigated on the platinum nanoparticles modified copper/titanium catalysts (PtNPsCu/Ti), which were fabricated by employing the electroless copper plating and galvanic displacement technique. ICP-OES, XRD, FESEM, and EDX have been used to characterize PtNPsCu/Ti catalysts’ composition, structure, and surface morphology. The oxidation of sodium borohydride was examined on the PtNPsCu/Ti catalysts using cyclic voltammetry and chrono-techniques.

Electrochemical behaviour of silver in aqueous chromate solutions

1998 ◽  
Vol 76 (8) ◽  
pp. 1156-1161 ◽  
Author(s):  
Sayed S Abd El Rehim ◽  
Magdy AM Ibrahim ◽  
Hamdy H Hassan ◽  
Mohammed A Amin
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Behaviour ◽  
Anode Surface ◽  
Cyclic Voltammograms ◽  
Oxidation Peak ◽  
Surface Layers ◽  
Compact Layer ◽  
X Ray ◽  
Solid Films ◽  
Scan Rate

The electrochemical behaviour of silver was studied under cyclic voltammetry and chronoamperometry conditions in aqueous K2CrO4 solutions. The forward cyclic voltammograms exhibited one oxidation peak, A1, due to the formation of Ag2CrO4. The height of the anodic peak, A1, increases with increasing chromate concentration, temperature, and scan rate. The solid films formed on the anode surface have been examined by X-ray diffractometry. The reverse voltammograms exhibited two reduction peaks, C1 and C2, indicating the formation of two distinct surface layers of Ag2CrO4, an inner compact layer reduced in peak C1 and an outer powdery layer reduced in peak C2.Key words: silver electrode, cyclic voltammetry, K2CrO4 solutions.

A Porous Carbon Prepared by Using a Mordenite Mineral as Template and its Cyclic Voltammetry Study in H2SO4

2010 ◽  
Vol 143-144 ◽  
pp. 749-752
Author(s):  
Gui Yang Liu ◽  
Yan Nan Li ◽  
Jun Ming Guo ◽  
Bao Sen Wang
Keyword(s):  
Cyclic Voltammetry ◽  
Phase Composition ◽  
Rate Capability ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scan Rate ◽  
Micro Morphology ◽  
Good Rate Capability ◽  
Templated Carbon

A natural mordenite mineral has been used as a template to prepare a templated carbon. X-ray diffraction (XRD), nitrogen adsorption, scanning electric microscope (SEM) and cyclic voltammetry (CV) are used to analyze the phase composition, pore structure, micro morphology and electrochemical performance. The specific surface area of the templated carbon is 724m2/g, and the mesoporosity is high to 63.8%. In H2SO4 medium, the carbon has large capacity and good rate capability. The capacity of the carbon decreases from 103 to 94F/g (the capacity remains more than 92%) when the scan rate increases from 10 to 200mV/s. The CV curve of the templated carbon exhibits rectangle-like shape, and the shape keeps well at high scan rate.

Preparation and Performance of Co3O4/Polyaniline Nano-Composite for Supercapacitor

2011 ◽  
Vol 239-242 ◽  
pp. 2042-2045 ◽  
Author(s):  
Shu Ping Yu ◽  
Xiao Cong Chang ◽  
Zhong Ming Wang ◽  
Ke Fei Han ◽  
Hong Zhu
Keyword(s):  
Cyclic Voltammetry ◽  
Emulsion Polymerization ◽  
Cobalt Oxide ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Nano Composite ◽  
X Ray ◽  
Scan Rate ◽  
And Performance

Cobalt oxide-Polyaniline (Co3O4/PANI) nanocomposites were prepared via inverted emulsion polymerization. The structure of the obtained composites were characterized by X-ray diffraction (XRD). The electrochemical behavior was studied by cyclic voltammetry(CV) and electrochemical impedance spectrometry(EIS) experiments. The Co3O4/PANI(1:2) composite calcined at 400°C exhibits the highest capacitance value of 357 F/g at the scan rate of 5mV/s.

Excellent Rate Capability in H2SO4 of a Porous Carbon Prepared by Template Method Using a Mazzite Mineral as Template

2011 ◽  
Vol 230-232 ◽  
pp. 1173-1176
Author(s):  
Gui Yang Liu ◽  
Yan Nan Li ◽  
Jun Ming Guo ◽  
Bao Sen Wang
Keyword(s):  
Cyclic Voltammetry ◽  
Phase Composition ◽  
Electrochemical Performance ◽  
Porous Carbon ◽  
Rate Capability ◽  
Template Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Scan Rate

A porous carbon was prepared by template method using a mazzite mineral as a template. X-ray diffraction (XRD), nitrogen adsoption, scanning electric microscope (SEM) and cyclic voltammetry (CV) were used to investigate the phase composition, pore structure, morphology and electrochemical performance of the carbon. The surface area of the carbon is 511m2/g. The pores of the carbon are mcropores and mesopores. In H2SO4 medium, the carbon exhibits a low capacity and a rectangle-like shaped CV curve at low scan rate. When the scan rate increases from 10 to 200mV/s, the capacity decreases only from 47 to 41F/g, and the rectangle-like shape keeps well. The carbon exhibits an excellent rate capability.

Effect of Reducing Agent on the Dispersion of Pt Nanoparticles on Electrospun Nb0.1Ti0.9O2 Nanofibers

2013 ◽  
Vol 1542 ◽  
Author(s):  
Esmaeil Navaei Alvar ◽  
Biao Zhou ◽  
S. Holger Eichhorn
Keyword(s):  
Electron Microscopy ◽  
Ethylene Glycol ◽  
Surface Area ◽  
Sodium Borohydride ◽  
Chemical Reduction ◽  
Pt Nanoparticles ◽  
Surfactant Solution ◽  
Pem Fuel Cells ◽  
Active Surface Area ◽  
X Ray

ABSTRACTDegradation of the catalyst and catalyst support is an essential limitation of polymer electrolyte membrane (PEM) fuel cells containing commercial platinum on carbon catalysts. Catalysts based on platinum nanoparticles coated onto nanostructured TiO2 materials are presently investigated as a more stable and equally cost effective alternative. Reported here is the synthesis of two different Pt/Nb0.1Ti0.9O2 catalysts that were prepared by chemical reduction of H2PtCl6 with either sodium borohydride in ethanolic surfactant solution or ethylene glycol. X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy confirmed the deposition of Pt nanoparticles on the surface of the nanofibers and revealed average sizes of 5.4 nm and 7.6 nm for reduction with ethylene glycol and sodium borohydride, respectively. The formation of smaller sized Pt nanoparticles in ethylene glycol is reasoned with the passivation of the nanoparticle surface by glycolic anions. Cyclic voltammetry measurements confirmed a higher electrochemical specific surface area (ESCA) of about 5.45 m2/gPt for the catalyst with smaller nanoparticles while the other catalyst reached only 4.96m2/gPt. Both catalysts retain about 60% of their electrochemically active surface area after 1000 voltammetric cycles in the range of 0.03 to 1.4 V vs. RHE. This relatively high value of activity retention is explained with a strong interaction between Pt nanoparticles and Nb0.1Ti0.9O2 support.

Hydrophobic Ferrocene Derivatives as Potential Standards in Electrochemistry

1997 ◽  
Vol 62 (2) ◽  
pp. 185-198 ◽  
Author(s):  
Jaroslav Podlaha ◽  
Petr Štěpnička ◽  
Róbert Gyepes ◽  
Vladimír Mareček ◽  
Alexander Lhotský ◽  
...  
Keyword(s):  
Surface Tension ◽  
Cyclic Voltammetry ◽  
Redox Potential ◽  
Diffusion Coefficients ◽  
Carbon Electrodes ◽  
X Ray Diffraction ◽  
Ferrocene Derivatives ◽  
X Ray ◽  
Special Cases ◽  
As Solubility

Ferrocene (FcH) derivatives monosubstituted by palmitoyl (1), hexadecyl (2), 1-adamantoyl (3) or 1-adamantylmethyl (4) groups were sythesized and characterized by NMR, mass and 57Fe Mossbauer spectroscopy. The structure of 1-adamantoylferrocene was determined by single-crystal X-ray diffraction. Cyclic voltammetry on gold and glass-like carbon electrodes demonstrated that the compounds can serve as electrochemical standards for special cases since their ferrocene/ferricinium redox potential remains stable and reversible, while the properties such as solubility, diffusion coefficients and surface tension are strongly solvent-dependent.

On the theory of cyclic voltammetry for multiple nucleation and growth: Scan rate influence

2021 ◽  
Vol 883 ◽  
pp. 115056
Author(s):  
Alexander V. Kosov ◽  
Olga V. Grishenkova ◽  
Olga L. Semerikova ◽  
Vladimir A. Isaev ◽  
Yurii P. Zaikov
Keyword(s):  
Cyclic Voltammetry ◽  
Nucleation And Growth ◽  
Scan Rate
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