Cu2S/NixSy multi-interfaces induced Ni(iii) for optimizing alkaline hydrogen evolution reaction

Abstract

Regulating an extraordinary metal high valence state to optimize the performance of the hydrogen evolution reaction (HER) presents an intriguing pathway. Herein, we successfully constructed Cu₂S/Ni_xS_y-n (where n represents the ratio of added Cu to Ni) catalysts with high value nickel by introducing Cu into NiS through a simple one-pot method, which exhibited excellent HER performance. This excellent HER catalytic performance was attributed to the high valency of Ni induced by the introduction of an appropriate amount of Cu, which enhanced the adsorption of hydrogen atoms and facilitated the HER process. Meanwhile, the multi-interface structure between Cu₂S and Ni_xS_y regulated the electronic structure, which was beneficial for improving the HER activity and electrical conductivity. Thus, this work describes a novel route for modifying transition-metal electronic structures by regulating the oxidation states of high valency metals.