Conference Papers
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Item Electrodeposition and electrocatalytic study of Ni-W alloy coating(Trans Tech Publications Ltd ttp@transtec.ch, 2015) Elias, L.; Hegde, A.C.Electrocatalytically active Ni-W alloy coatings have been developed through compositionally versatile electrodeposition method on copper substrate from tri-sodium citrate bath, using glycerol as the additive. The deposition conditions have been optimized for peak performance of their electrocatalytic behavior, like hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1M KOH. Corrosion behaviors of the coatings have also been tested under study conditions of electrocatalysis. Electrocatalytic behaviors were tested by cyclic voltammetry (CV) and chronopotentiometry techniques. Experimental results demonstrated that Ni-W alloy coatings, deposited at low and high current densities (c. d.) were showing superior performance for OER and HER, respectively. Better electrocatalytic activity for HER with increase of deposition c. d. was attributed by the unique phase structure, surface morphology and chemical composition of the coatings, confirmed by XRD, SEM and EDX analysis. The dependency of coating thickness and hardness on HER and OER were analyzed, and results are discussed. © (2015) Trans Tech Publications, Switzerland.Item Electrodeposited Ni-P alloy thin films for alkaline water splitting reaction(Institute of Physics Publishing michael.roberts@iop.org, 2016) Elias, L.; Damle, V.H.; Hegde, A.Ni-P alloy thin films was developed as a robust electrode material for alkaline water splitting for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), through electrodeposition technique. The influence of alloy composition, achieved through induced codeposition of the reluctant non-metal, i.e. phosphorous (P) on its electrocatalytic activity was studied, and arrived at the best composition of alloy for HER and OER. The water splitting efficacy of the alloy films was tested in 1.0 M KOH using electrochemical methods such as cyclic voltammetry and chronopotentiometry. The experimental observation shows that the alloy thin film with 9.0 wt.% of P and 4.2 wt.% of P are the best electrode materials for HER and OER, respectively. The electrocatalytic performance of alloy films towards HER and OER were related to its surface topography, composition and crystal structure through field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses, respectively. © Published under licence by IOP Publishing Ltd.Item Synthesis of Ni-W-Graphene oxide composite coating for alkaline hydrogen production(Elsevier Ltd, 2018) Elias, L.; Hegde, A.Nickel-Tungsten-Graphene oxide (Ni-W-GO) composite coating was developed through direct electrolysis method, and its electrocatalytic activity for alkaline water splitting reaction was studied. The development of composite coating with a homogeneous dispersion of GO was achieved using an optimal Ni-W plating bath loaded with GO. The electrocatalytic efficacy of the coating for hydrogen evolution reaction (HER) was tested using cyclic voltammetry and chronopotentiometry techniques in 1.0 M KOH medium. The variation in electrocatalytic activity with the addition of GO was studied. A significant increase in the electrocatalytic activity towards HER was found. The improvement in electrocatalytic activity of Ni-W-GO composite coating was ascribed to the intersticed GO nanoparticles in the alloy matrix, evidenced by different advanced methods of analyses, like Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). © 2018 Elsevier Ltd.Item A comparative study on the electrocatalytic activity of electrodeposited Ni-W and Ni-P alloy coatings(Elsevier Ltd, 2018) Elias, L.; Hegde, A.Bright Ni-W and Ni-P alloy coatings were synthesized through direct electrolysis from an aqueous alkaline citrate bath. The effect of alloying elements, W and P, on the electrocatalytic activity of Ni was studied, based on their induced codeposition behavior and related to the composition, structure and surface morphology of the developed coatings. The electrocatalytic activity of the alloy coatings towards hydrogen evolution reaction (HER) was studied using electrochemical techniques such as cyclic voltammetry (CV) and chronopotentiometry (CP), in 1. M KOH medium. A comparison of the electrocatalytic efficiencies of these Ni-based alloys was made in consideration with its physical and electrochemical characteristics. The obtained results showed that the alloying of Ni with W gives superior properties towards HER, attributed by its better hydrogen adsorption energy than in Ni-P alloy. The surface appearance, chemical composition and phase structure of the coatings were studied using SEM, EDS and XRD analyses, respectively. © 2018 Elsevier Ltd. All rights reserved.