An Ag2S-engineered heterojunction enhances the overall water splitting efficiency of NiSx catalysts

Abstract

Ag₂S/NiS_x heterostructures are designed as efficient electrocatalysts for overall water splitting. Ag₂S modifies the electronic structure and induces a large number of active sites. Strong interactions between the interfaces of the heterostructure lead to lower charge transfer resistance and enhance the intrinsic activity of active sites. As expected, Ag₂S/NiS_x demonstrated excellent OER catalytic performance in alkaline environments, with OER current densities of 10, 50, and 100 mA cm⁻² obtained in 1 M KOH at overpotentials of only 42, 137, and 180 mV. When used in a two-electrode electrolyzer, Ag₂S/NiS_x can achieve 100 mA cm⁻² at a low voltage of 1.81 V. This work provides an efficient way to enhance the overall catalytic performance of non-precious metal electrocatalysts.