Synergistic Interfacial and Doping Engineering of Heterostructured NiCo(OH)x-CoyW as an Efficient Alkaline Hydrogen Evolution Electrocatalyst

To achieve high efficiency of water electrolysis to produce hydrogen (H-2), developing non-noble metal-based catalysts with considerable performance have been considered as a crucial strategy, which is correlated with both the interphase properties and multi-metal synergistic effects. Herein, as a proof of concept, a delicate NiCo(OH)(x)-Co-y W catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by an electrochemical etching-growth process, which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction, with an overpotential of 21 and 139 mV at 10 and 500 mA cm(-2), respectively. Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)(x)/Co-y W heterogeneous interface resulted in favorable electron redistribution and faster electron transfer efficiency. The amorphous NiCo(OH)(x) strengthened the water dissociation step, and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H-2 desorption. In addition, NiCo(OH)(x)-CoyW exhibited desirable urea oxidation reaction activity for matching H-2 generation with a low voltage of 1.51 V at 50 mA cm(-2). More importantly, the synthesis and testing of the NiCo(OH)(x)-CoyW catalyst in this study were all solar-powered, suggesting a promising environmentally friendly process for practical applications.

Automated summary

Non-noble metal-based catalysts with heterostructure and multi-metal synergistic effects show promise for efficient water electrolysis to produce hydrogen, with improved activity and electron transfer efficiency.