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/Cu₂S 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/Cu₂S and enhanced the performance of electrocatalytic hydrogen evolution reaction (HER). Compared with Cu(OH)₂, Cu(OH)₂/Cu₂S showed better alkaline HER performance, especially when the vulcanization concentration was 0.1 M, the overpotential of Cu(OH)₂/Cu₂S 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.