Synergistic Interfacial and Doping Engineering of Heterostructured NiCo(OH)(x)-Co(y)W 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)-Co(y)W 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)-Co(y)W catalyst in this study were all solar-powered, suggesting a promising environmentally friendly process for practical applications. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40820-021-00639-x.