A cobalt-doped WS₂/WO₃ nanocomposite electrocatalyst for the hydrogen evolution reaction in acidic and alkaline media

The development of earth-abundant and green electrocatalysts is an important research field, aiming to provide energy solutions by clean and efficient hydrogen evolution (HER). 2D transition metal dichalcogenides (TMDs) are well-known HER catalysts, and some are even biocompatible and environmentally friendly, such as WS₂. Synthesizing them in a flower-like morphology that provides abundant edges, and the formation of composite structures that offer multiple interfaces, render them with promising features for electrocatalysis. Here we show the synthesis of WS₂/WO₃ hybrid catalysts, which facilitate the hydrogen evolution reaction. The mixture of 1T/2H-WS₂ phases and doping with various transition metals (Fe, Co, and Ni) improves the pristine structures. The 5% Co-WS₂/WO₃ composite is the most promising HER electrocatalyst among the doped catalysts studied here. These Co-doped WS₂/WO₃ composites represent another TMD alternative to the precious metal electrocatalysts for the HER.