Preparation of Cu(OH)2/Cu2S arrays for enhanced hydrogen evolution reaction

Abstract Cu(OH) 2 has the advantages of ease of structural regulation, good conductivity, and relatively low cost, making it a suitable candidate material for use as an electrocatalyst. However, its catalytic efficiency and stability still need to be improved further. Therefore, Cu(OH) 2 /Cu 2 S was successfully prepared on copper foam (CF) using the in situ growth and hydrothermal method. The structural characterization showed that sulfidation treatment induced transformation of Cu(OH) 2 /CF from smooth nanorods into a coral‐like structure, which exposed more active sites of Cu(OH) 2 /Cu 2 S and enhanced the performance of electrocatalytic hydrogen evolution reaction (HER). Compared with Cu(OH) 2 , Cu(OH) 2 /Cu 2 S showed better alkaline HER performance, especially when the vulcanization concentration was 0.1 M, the overpotential of Cu(OH) 2 /Cu 2 S was 174 mV, and the reaction kinetics was 64 mv dec −1 at a current density of 10 mA cm −2 . In this work, the morphology and electronic structure of copper‐based metal sulfide electrocatalysts were adjusted by sulfide treatment, which provided a new reference for improving HER performance.