Morphology and Stoichiometry Dependent Electrocatalytic Activity of Cu2ZnSnS4 for Hydrogen Evolution Reaction (HER) with Addition of Nonionic Surfactants

Abstract

In this work, hierarchical Cu₂ZnSnS₄ electrocatalysts with different morphologies and stoichiometries were synthesized via the hydrothermal method and their electrocatalytic performances in hydrogen evolution reaction were evaluated. The morphologies of Cu₂ZnSnS₄ electrocatalysts were modulated by adjusting the content of surfactants during the hydrothermal process. The stoichiometries of as-prepared Cu₂ZnSnS₄ were found to be Cu₂Zn_0.8Sn_0.7S_2.9, Cu₂Zn_0.7Sn_1.2S_4.7 and Cu₂Zn_0.5Sn_0.7S_3.2 for the absence of surfactant and the addition of polyethylene glycol-(400) (PEG 400) and octylphenol polyoxyethyleneether-10 (OP 10) respectively. The Cu₂ZnSnS₄ synthesized with the addition of PEG 400 displayed superior electrocatalytic activity in acid medium with an overpotential of 295 mV obtained at 10 mA cm^− 2 and a Tafel slope of 133 mV dec^− 1. This work reveals that the stoichiometry and microstructure of Cu₂ZnSnS₄ are critically important for its electrocatalytic activity while have less impact on the electrocatalytic durability, and provides useful information to explore the utilization of chalcogenides as the attractive electrocatalysts.