Catalytic Interface of rGO-VO/WO Hydrogel for High-Performance Electrochemical Water Oxidation.

The continuous increase in global energy demand necessitates the development of sustainable, clean, and highly efficient methods of energy generation. Electrochemical water splitting, comprising hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), represents a promising strategy but remains hindered by sluggish reaction kinetics and limited availability of highly active electrocatalysts especially under alkaline conditions. Addressing this challenge, we successfully synthesized a rGO-VO/WO (rG-VO/WO) hydrogel electrocatalyst through a facile hydrothermal approach. The prepared composite distinctly reveals an advantageous hierarchical microstructure characterized by VO nanoflakes uniformly distributed on the surface of rGO nanosheets, intricately integrated with WO nanorods. Evaluated in a 1.0 M KOH electrolyte, the optimized rG-VO/WO-2 catalyst demonstrates remarkable electrocatalytic performance towards OER, achieving a low overpotential of 265.8 mV and a reduced Tafel slope of 81.9 mV dec. Furthermore, the catalyst maintains robust stability with minimal performance degradation, exhibiting an overpotential of only 273.0 mV after 5000 cyclic stability tests. The superior catalytic activity and durability are attributed to the synergistic combination of enriched chemical composition, effective electron transfer, and abundant catalytic active sites inherent in the well-optimized rG-VO/WO-2 composite.