Conference Papers
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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.Item Electrodeposition of Ni-Mo alloy coatings for water splitting reaction(American Institute of Physics Inc. subs@aip.org, 2018) Shetty, A.R.; Hegde, A.C.The present study reports the development of Ni-Mo alloy coatings for water splitting applications, using a citrate bath the inducing effect of Mo (reluctant metal) on electrodeposition, its relationship with their electrocatalytic efficiency were studied. The alkaline water splitting efficiency of Ni-Mo alloy coatings, for both hydrogen evolution reaction (HER) and oxygen evolution reaction were tested using cyclic voltammetry (CV) and chronopotentiometry (CP) techniques. Moreover, the practical utility of these electrode materials were evaluated by measuring the amount of H2 and O2 gas evolved. The variation in electrocatalytic activity with composition, structure, and morphology of the coatings were examined using XRD, SEM, and EDS analyses. The experimental results showed that Ni-Mo alloy coating is the best electrode material for alkaline HER and OER reactions, at lower and higher deposition current densities (c. d.'s) respectively. This behavior is attributed by decreased Mo and increased Ni content of the alloy coating and the number of electroactive centers. © 2018 Author(s).