Fabrication of Ni-Polyaniline/Graphene Oxide Composite Electrode with High Capacitance and Water Splitting Activity.

The Ni-PANI@GO composite electrode was fabricated via cost effective electrodeposition technique. According to the XRD, FTIR, Raman, SEM, and XPS analyses revealed that the nickel doped PANI@GO composite has been fabricated on the surface of the nickel foam. Addition of nickel significantly enhanced interaction between graphene with PANI leading to higher degree of polyaniline doping though imine groups. Electrochemical investigation revelated the significant performance of the Ni-PANI@GO composite electrode, boosting an impressive capacitance of 4480 F/g at 40 A/g, surpassing previous Ni-foam-based binder-free electrodes. Notably, Ni-PANI@GO electrode displayed excellent catalytic activity in both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), generating a considerable volume of the gas bubbles at relatively modest overpotentials of 279 mV and 244 mV respectively. This event allows for the achievement of 20 mA cm-2 current density. Furthermore, in the laboratory-scale water electrolyzer, a low cell voltage of 1.72 V was achieved, facilitating a water-splitting current density of 20 mA cm-2. This study underscores the premising potential for the real-world device's application of the versatile Ni-PANI@GO composite electrode.