Highly efficient NiCo/VN electrocatalyst co-facilitated by interfacial engineering and support effect for large-current-density alkaline water/seawater hydrogen evolution reaction

Abstract

Developing efficient and continuously stable water electrolysis catalysts to cope with harsh industrial conditions remains a huge challenge in the alkaline seawater electrolysis hydrogen production process. Transition metal nitrides are potential catalysts for seawater electrolysis, but they are still being modified to further improve catalytic performance. Here, a nanosheet-like NiCo/VN heterostructure electrocatalyst was prepared. The heterogeneous interface formed between and VN and NiCo alloy and the strong metal-support interaction regulate the electronic structure and optimizes the adsorption and desorption of intermediates. Moreover, the introduction of the NiCo alloy greatly facilitates the water dissociation step. Therefore, the prepared NiCo/VN catalyst exhibits excellent alkaline HER performance, with a low overpotential of 38 mV and 318 mV at a current density of 10 mA cm−2 and 1000 mA cm−2, shows high durability in 50 h of constant current tests at current densities of 10, 100, and 1000 mA cm−2 in alkaline seawater. This work proposes an effective strategy for preparing multiphase electrocatalysts, and the mechanism research fully confirms that it can promote the dissociation of water and the adsorption and desorption of intermediates.