A Shalini; P. Paulraj; k. Pandian; G. Anbazhagan; V. Jaisankar
Abstract
Synthesis of graphene oxide has entice good dispense of consciousness due to their vast utilization in different fields in modern days. In the present investigation, we report on the preparation of graphene oxide via a modified Hummer’s method. The nanocomposite were isolated and then characterized ...
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Synthesis of graphene oxide has entice good dispense of consciousness due to their vast utilization in different fields in modern days. In the present investigation, we report on the preparation of graphene oxide via a modified Hummer’s method. The nanocomposite were isolated and then characterized by using various analytical techniques to understand the composition and the surface morphology of the nanocomposites. The structure as well as morphology of the nanocomposites were analyzed using SEM Instruments. The electro chemical behavior of the compound was studied by cyclic voltammetry in various supporting electrolyte. The electrocatalytic behavior of the nanocomposites monitored over the oxidation of nitric oxide (NO). Copyright © VBRI Press.
Ankur Soam; Rajiv Dusane
Abstract
The development of micro-supercapacitor (µ-SC) based on silicon nanowires (SiNWs) has increased the demands ofcost-effective methods via low temperature processing routes for the fabrication of SiNWs which can enable the realization of µ-SC directly on a Si chip. In this work, SiNWs synthesized ...
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The development of micro-supercapacitor (µ-SC) based on silicon nanowires (SiNWs) has increased the demands ofcost-effective methods via low temperature processing routes for the fabrication of SiNWs which can enable the realization of µ-SC directly on a Si chip. In this work, SiNWs synthesized by hot-wire chemical vapor processing (HWCVP) at low substrate temperature of 350 oC have been explored as the electrodes for the use in µ-SC. Electrochemical behavior was tested by using cyclic voltammetry (CV) and galvanostatic charging/discharging in an ionic electrolyte. TEM characterization reveals as-grown SiNWs have inner crystalline core (c-core) sheeted with an amorphous layer of silicon (a-Si) which has poor electrical conductivity and reduces the capacitance of SiNWs. Copyright © 2017 VBRI Press.
Bikash Mandal; I. Basumallick; Susanta Ghosh
Abstract
Highly dispersed, porous and nano-sized FePO4 have been synthesized by a facile aqueous and alcoholic medium for their application as cathode in rechargeable lithium batteries. Various dispersing templates in association with suitable solvents are used to introduce porosity and dispersive nature among ...
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Highly dispersed, porous and nano-sized FePO4 have been synthesized by a facile aqueous and alcoholic medium for their application as cathode in rechargeable lithium batteries. Various dispersing templates in association with suitable solvents are used to introduce porosity and dispersive nature among the particles and to reduce the size of the particles. Characterization with FTIR, powder XRD and SEM suggests the formation of less crystalline, pure FePO4 with high surface area and high porosity. Cyclic voltametry has been employed to test the intercalation behaviour of lithium ions and confirms the reversible nature of the material. The role of the dispersing template for the material growth and the electrochemical performances of the synthesized FePO4 as cathode in lithium battery have been discussed. It is found that poly(styrene-co-divinylbenzene) as the dispersing agent produces highly dispersed material with highest discharge capacity of 138 mAh.g-1. Copyright © 2017 VBRI Press.
Poonam R. Kharangarh; Akshay Kumar; Raj K. Sharma; Gurmeet Singh
Abstract
With an objective to develop electrode materials with high specific capacitance and good stability, we prepared Graphene quantum dot-doped with transition metal of HCl by using a facile hydrothermal at different temperatures (~ 800C- 1400C). Samples were characterized by Raman spectroscopy, Powdered ...
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With an objective to develop electrode materials with high specific capacitance and good stability, we prepared Graphene quantum dot-doped with transition metal of HCl by using a facile hydrothermal at different temperatures (~ 800C- 1400C). Samples were characterized by Raman spectroscopy, Powdered X-ray Diffraction (PXRD), U-V Visible Spectroscopy, and Transmission Electron Spectroscopy (TEM). Raman spectroscopy study reveals intensity ratio alters with changes in temperatures. It was found the variation in size with doped GQDs under different temperature conditions from TEM measurements. The observed blue shifts in the energy gap of HCl doped GQDs at higher temperature are attributed to the strong interaction of GQDs with HCl. Electrochemical studies showed a superior strategy for generating transition metals doped GQDs. The higher electrochemical activity has been originated by using cyclic voltammetry of HCl doped GQDs at 1200C and is found to be superior electrodes than all other heated samples. The simplicity of synthesized material suggests electrode to understand the charge storage mechanism for commercial applications. Copyright © 2017 VBRI Press.
Basu M. Daas; Debalina Das; Susanta Ghosh
Abstract
Present study reports electro-oxidation of ethanol over platinum loaded, reduced graphene oxide – ZSM-5 composite (GO-ZSM) on graphite foil (GF). To prepare the Pt/r(GO-ZSM)/GF electrode, GO-ZSM-5 composite was prepared by simple 1:1 mechanical mixing which was coated over graphite foil and electrochemically ...
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Present study reports electro-oxidation of ethanol over platinum loaded, reduced graphene oxide – ZSM-5 composite (GO-ZSM) on graphite foil (GF). To prepare the Pt/r(GO-ZSM)/GF electrode, GO-ZSM-5 composite was prepared by simple 1:1 mechanical mixing which was coated over graphite foil and electrochemically reduced at a current density of (-)1 mA.cm-2. The electro-chemical studies, such as cyclic voltammetry and chronoamperometry established that Pt/r(GO-ZSM-5)/GF electrode exhibited better tolerance towards CO-poisoning compared to Pt/rGO/GF electrode. The larger IF:IB value for Pt/r(GO-ZSM)/GF indicated much lesser carbonaceous accumulation on the zeolite modified electrode. The peak current density was comparable for both Pt/r(GO-ZSM-5)/GF and Pt/rGO/GF electrodes. Thus ZSM-5 was instrumental in reducing the catalyst poisoning without compromising with the current density. The findings of the investigation can prove useful in the search of solution for the problem of catalyst poisoning associated with platinum electrodes.
Snehal L. Kadam; Pallavi M.Padwal; Sagar M.Mane; Shrinivas B.Kulkarni
Abstract
MnO2 metal oxide electrode material is synthesized by simple electrodeposition method on stainless steel substrate. The crystal structure and surface morphological characterizations of the obtained electrode are carried out by using X-ray diffraction (XRD) technique and Field Emission-Scanning Electron ...
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MnO2 metal oxide electrode material is synthesized by simple electrodeposition method on stainless steel substrate. The crystal structure and surface morphological characterizations of the obtained electrode are carried out by using X-ray diffraction (XRD) technique and Field Emission-Scanning Electron Microscopy (FE-SEM) respectively. The FE-SEM micrographs show highly porous well developed interconnected uniform nanosphere like morphology. The electrochemical properties of MnO2 electrode like Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) etc are studied in a 0.5 M Na2SO4 solution as electrolyte. The maximum specific capacitance is 543 F/g at scan rate 5 mVs-1 obtained from cyclic voltammetry (CV). The electrochemical stability of MnO2 electrode is investigated using cyclic voltammetry for 1000 cycles. The MnO2 electrode exhibits good cycling stability for 1000 cycles at scan rate100 mVs-1. The values of energy density and power density of MnO2 electrode material obtained from Galvanostatic charge-discharge studies. From all the electrochemical properties of MnO2 electrode, it indicates that it will be promising electrode material for supercapacitor application.
Mahima Khandelwal; Anil Kumar; Richa Baronia; Shraddha Tiwari; Avanish K. Srivastava; Surinder P. Singh; Sunil K. Singhal
Abstract
In the present work we report a facile method for the synthesis of Pt nanoparticles supported reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs) nanocomposite by an in-situ chemical reduction. The incorporation of MWCNTs to rGO leads to decrease in agglomeration between rGO sheets ...
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In the present work we report a facile method for the synthesis of Pt nanoparticles supported reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs) nanocomposite by an in-situ chemical reduction. The incorporation of MWCNTs to rGO leads to decrease in agglomeration between rGO sheets due to π – π interactions and higher loading of Pt nanoparticles. In this process, a mixture of exfoliated graphene oxide, CNTs and chloroplatinic acid was treated with a mixture of hydrazine hydrate and ammonium hydroxide at 95° C in an oil bath for 1 h. Pt nanoparticles of 4-6 nm size were homogeneously dispersed on rGO-CNTs nanocomposite as revealed by TEM analysis. Cyclic voltammetry measurements depict an anodic current density of 11.74 mA/cm2 that could be obtained using Pt/rGO-CNTs catalyst and 6.2 mA/cm2 using Pt/rGO catalyst during methanol oxidation, indicating that the catalytic activity of Pt/rGO-CNTs catalyst is almost 2 times higher than that of Pt/rGO catalyst. The electrochemical stability of Pt/rGO-CNTs catalyst was also found to be much higher as compared with that of Pt/rGO catalyst. Thus, Pt/rGO-CNTs catalyst has the potential to be used in the preparation of a promising anode material for direct methanol fuel cell. Copyright © 2016 VBRI Press
M. Kanakadurga; S. R. Murthy; Arya Das; Rakesh K. Sahoo; Saroj K. Singh
Abstract
ZnO nano-platelets have been prepared using a high pressure reactor via hydrothermal route. The as-formed fine platelets morphology of the as-synthesized powder was confirmed from the scanning electron microscopy (SEM) images. The elemental analysis using energy dispersive X-ray (EDAX) analysis indicated ...
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ZnO nano-platelets have been prepared using a high pressure reactor via hydrothermal route. The as-formed fine platelets morphology of the as-synthesized powder was confirmed from the scanning electron microscopy (SEM) images. The elemental analysis using energy dispersive X-ray (EDAX) analysis indicated the presence of Zn, O, Na and Cl which confirms the presence of ZnO as major and NaCl as the minor phase. The precipitation of this minor phase after growth and catalytic induction in nano-platelet (NP) morphology during growth has been elucidated. The electrochemical performance of this as-synthesized powder is quite promising. Additionally, the effect of this minor NaCl phase in changing the ionic equilibrium of the electrolyte in capacitance measurement has been analyzed.
