Electrodeposition of Co-Ni-W ternary alloy electrode materials from ethylene glycol electrolyte and their catalytic performance for hydrogen evolution reaction

Hydrogen energy, as a sustainable and efficient energy option, possesses immense potential to address energy shortages and mitigate climate change impacts. To advance alkaline water electrolysis, the development of effective and robust non-noble metal catalysts is essential. This study reports “coral island-like” structure Co-Ni-W ternary alloy electrode materials synthesized via electrodeposition in an ethylene glycol (EG) organic solvent. By precisely controlling W 6+ concentration, Co-Ni-W ternary alloys with excellent hydrogen evolution reaction (HER) catalytic performance are obtained. Cyclic voltammetry (CV) records demonstrated that Co 2+ and Ni 2+ are capable of facilitating the reduction of W 6+ , and the co-deposition of Co-W, Ni-W and Co-Ni-W alloys is governed by a typical induced co-deposition mechanism. The W content significantly affects the HER catalytic performance of the Co-Ni-W ternary alloys, increasing initially and then decreasing. The Co 46 Ni 29 W 25 ternary alloy displays an optimal HER catalytic activity and stability with an electrochemical active surface area (ECSA) of 1925 cm 2 and a hydrogen evolution overpotential ( η 10 ) of 63 mV. This study demonstrates that Co-Ni-W ternary alloy is a potential contender for alkaline water electrolysis hydrogen evolution.