Faculty Publications
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Item Synthesis of effective electrocatalyst for water splitting application from simple Cu-Ni bath(Allerton Press Incorporation journals@allertonpress.com, 2017) Elias, L.; Banjan, R.U.; Hegde, A.C.Electrocatalytically active Cu-Ni alloy coatings have been developed from a simple electrolyte having only Cu+2 and Ni+2 ions, without the use of any additive. Electrocatalytic character of the coatings was tested for their hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1.0 M KOH medium, alongside with their corrosion behaviours. Cyclic voltammetry and chronopotentio-metry study revealed that the deposition current density has a prominent role on the alkaline water splitting behaviour of the coatings, depending on their phase structure, composition and surface morphology. It was found that the c.d. has an inverse dependence on HER and OER. The Cu-Ni alloy coatings developed, respectively at 3.0 and 4.0 A dm–2, were found to be the best coatings for HER and OER, depending on the surface morphology. The electrocatalytic activity of Cu-Ni alloy coating for HER, deposited at 3.0 A dm–2 (optimal), was further improved through electrochemical dissolution of the as-deposited coating. The increase in the electrocatalytic activity for HER has been attributed to the enhancement in the exposed surface area of Ni active sites due to the leaching of Cu from the alloy matrices, evidenced by the energy-dispersive X-ray spectroscopy and scanning electron microscopy. The dependencies of HER and OER on to the surface of Cu-Ni alloy coatings were analysed in terms of deposition c.d. of the coatings, and the results are discussed. © 2017, Allerton Press, Inc.Item Development of Ni-W alloy coatings and their electrocatalytic activity for water splitting reaction(Elsevier B.V., 2020) Neethu, R.M.; Hegde, A.C.This study reports the electrodeposition of Nickel-Tungsten (Ni-W) alloy coatings and their efficiency as electrode material for water splitting applications. Ni-W alloy coatings were electrodeposited and their electrocatalytic activity towards alkaline water splitting for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 M KOH were studied. Cyclic voltammetry (CV) and chronopotentiometry (CP)techniques were used to quantify their electrocatalytic behaviors. It demonstrated the inverse dependency of electrocatalytic behaviors of coatings towards HER and OER at low and high c.d.'s, respectively. This is attributed to the change in the composition, in terms of Ni and W content of the alloy. The surface features, structural and compositional change of coatings, responsible for improved electrocatalytic activity were examined using Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Energy dispersive X-ray spectroscopy (EDS) techniques. Experiment results revealed that alloy deposit can be used as a potential material for water splitting applications. © 2020Item Anomalous codeposition of NiCo alloy coatings and their corrosion behaviour(Elsevier Ltd, 2022) Raveendran, M.N.; Hegde, A.C.Here, we report the electrodeposition NiCo alloy coatings from a new bath using the glycine, as additive. A bright and uniform coatings NiCo alloy have been developed at different current densities and their corrosion performances have been evaluated. The surface morphology, composition and phase structure of alloy coatings have been analyzed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction (XRD) techniques, respectively. The compositional information of NiCo alloy coatings revealed that the proposed bath follows anomalous type of codeposition over range of current density studied (1.0–4.0 A dm−2), by demonstrating more Wt. % of Co in the deposits, than in the bath. A constant increase in the Wt. % of Ni with current density was found, supported by XRD analyses; and it may be attributed to the depletion of more readily depositable Co+2 ions at cathode film by following the principle of codeposition of NiCo alloy. The corrosion study revealed that NiCo alloy deposited at 4.0 A dm−2, represented as (NiCo) 4.0 A dm-2 coating is the most corrosion resistant compared to all other coatings. The highest corrosion stability of (NiCo) 4.0 A dm-2 alloy attributed to its highest Ni content (38.6 wt%) and increased surface smoothness, supported by EDS and SEM study. © 2022