Ultrathin Nickel‐doped ZnIn₂S₄ Nanosheets with Sulfur Vacancies for Efficient Photocatalytic Hydrogen Evolution

Abstract

Abstract Introducing vacancies and element doping are effective approaches to boost photocatalytic activities of metal sulfides. In this work, sulfur vacancies and nickel dopants were simultaneously introduced into ultrathin ZnIn 2 S 4 nanosheets (ZIS NSs) to explore their synergistic role in promoting photocatalytic hydrogen evolution. The S vacancies can trap the photo‐generated electrons, lower the conduction band minimum (CBM), improve the photo‐generated charge reduction capacity and prolong the carrier lifetime. Meanwhile, Ni dopants cause an increase in the Fermi level (E F ), which ensures a higher charge density and an effective carrier separation efficiency. The optimum hydrogen evolution rate of sample Ni 0.05 −V S −ZIS reaches 8.91 mmol g −1 h −1 under visible light due to the synergistic effect of the S vacancies and Ni dopants.