N and Mo Dual Modulating Electronic Structure of NiS Nanosheet Arrays for Boosted Full Water Electrolysis

The design of a bifunctional electrocatalyst with stable performance and low cost is important for water electrolysis. In this article, a bifunctional electrocatalyst (Mo- and N-modified NiS nanosheet array grown on carbon paper, N-NiMoS/CP) has been prepared through an in situ vulcanization method. The modified catalyst exhibits high activity, good kinetics, and excellent durability with superior alkaline HER and OER performance. In particular, the N and Mo comodification synergistically modulates the electronic structure of NiS, combined with the optimized Ni electron density, promoting the Volmer process of the HER along with optimizing the adsorption of oxygen-containing intermediates to boost the OER in alkaline solution. As a result, the N-NiMoS/CP sample has a low overpotential (HER: η 10 = 120 mV; OER: η 10 = 270 mV). Additionally, it also indicates preferable full water electrolysis performance (cell voltage: 1.60 V at 10 mA cm –2 ). Such study illustrates a feasible perception for modulating the electronic densities of electrocatalytic sites by means of dual-decoration engineering and provides a path for designing optimized bifunctional electrocatalysts in water electrolysis systems.