Engineering 2D heterostructured VS₂-rGO-Ni nanointerface to stimulate electrocatalytic water splitting and supercapacitor applications

The electrochemical oxygen evolution reaction (OER) is a key anodic response that turns renewable energy into fuels. Overcoming the obstacles (sluggish kinetics) in OER requires the development of a highly active electrocatalyst with excellent stability. For the first time, this study presents a new kind of nanostructured morphology of VS2-rGO-Ni ternary system for alkaline OER. A systematic investigation was carried out to optimize the excellent electrocatalyst using different arrays in the binary and ternary composites. The homogeneous and well-interconnected network structure is identified between the VS2 nanosheets (similar to 20 nm thickness) and rGO layered structure, including the dispersion of Ni nanoparticles. The OER performances of VS2-rGO-Ni-3 (rVN-3) in 1 M KOH were excellently stimulated, where the overpotential was lowered to 192 mV at 10 mA cm(-2). After 2500 CV cycles and chronopotentiometry tests (10 mA cm(-2)), the electrocatalyst showed long-term stability without losing much activity. Although, the electrocatalysts were assembled in rVN-3||rVN-3 required cell voltage of 1.70 V which is able to achieve the threshold current density. The interfacial interaction between the VS2, rGO and Ni in the ternary composite leads to synergistic effect that significantly promotes the adsorption of oxygenated intermediates for an excellent OER process. Moreover, rVN-3 provided a reasonable supercapacitor performances, which confirms the multi characteristics properties. The nanostructured morphology with a well-connected network structure provides a large active surface for interacting with charge species and stable performance.