Synergistic d-p hybridized Co/W5N4 heterostructure catalyst for industrial alkaline water/seawater hydrogen evolution

Developing efficient and durable non-precious metal electrocatalysts with industrial current density is urgent for hydrogen evolution reaction from alkaline water/seawater but remains challenging. Here, a heterostructured Co/W5N4 catalyst with porous structure is innovatively constructed. The theoretical calculations confirm the strong d-p hybridization between Co and N at the interface of Co/W5N4 with the modulation of d‐band center of Co sites. The synergistic effect between Co and W5N4 is disclosed that H2O can rapidly dissociate on the W sites to generate H* adsorbed at the Co sites for favorable H2 production. Consequently, the Co/W5N4 catalyst affords low overpotentials of 113 and 118 mV to drive current density of 100 mA cm−2 in alkaline water/seawater electrolytes, respectively, which are even superior to those of commercial Pt/C. More importantly, it can also present outstanding HER stability at large current density of 500 mA cm−2 for over two weeks (350 h) in alkaline water/seawater electrocatalysis.