Electrodeposition of Ni-Mo-rGO composite electrodes for efficient hydrogen production in an alkaline mediumElectronic supplementary information (ESI) available. See DOI: 10.1039/c7nj04552b

• Main Authors: Shetty, Sandhya, Sadiq, M. Mohamed Jaffer, Bhat, D. Krishna, Hegde, A. Chitharanjan
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c7nj04552b

The mechanism and kinetics of the hydrogen evolution reaction (HER) on Ni-Mo-rGO composite electrodes in 1.0 M KOH solution were investigated by cyclic voltammetry (CV), chronopotentiometry (CP) and potentiodynamic polarization techniques. Ni-Mo-rGO composite coatings were deposited on a copper substrate by an electrodeposition method at a current density (c.d.) ranging from 1.0 to 4.0 A dm −2 . The change in surface morphology and chemical composition was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, energy dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS). It was shown that the carbon content of the composite coatings was affected by c.d. With the increase in the carbon content in the Ni-Mo-rGO composite coatings, the onset potential was decreased and the exchange current density was increased during the HER. The minimum onset potential and maximum exchange current density of Ni-Mo-rGO composite coatings for the HER were −401.6 mV and 4.31 μA cm −2 . The best composite coating exhibited a maximum peak current density of −0.517 A cm −2 at −1.6 V, which is approximately 3 times better than that of the binary Ni-Mo alloy, indicating the best activity for hydrogen production. The potentiodynamic polarization measurements revealed that composite coatings are much more resistant to corrosion than binary alloy coatings. Enhanced performance of Ni-Mo alloy coatings due to the incorporation of rGO into the alloy matrix via an electrodeposition method.