Construction of CoS2/Zn0.5Cd0.5S S‐Scheme Heterojunction for Enhancing H2 Evolution Activity Under Visible Light

Abstract In the field of photocatalysis, building a heterojunction is an effective way to promote electron transfer and enhance the reducibility of electrons. Herein, the S‐scheme heterojunction photocatalyst (CoS 2 /Zn 0.5 Cd 0.5 S) of CoS 2 nanospheres modified Zn 0.5 Cd 0.5 S solid solution was synthesized and studied. The H 2 evolution rate of the composite catalyst reached 25.15 mmol g −1 h −1 , which was 3.26 times that of single Zn 0.5 Cd 0.5 S, whereas pure CoS 2 showed almost no hydrogen production activity. Moreover, CoS 2 /Zn 0.5 Cd 0.5 S had excellent stability and the hydrogen production rate after six cycles of experiments only dropped by 6.19 %. In addition, photoluminescence spectroscopy and photoelectrochemical experiments had effectively proved that the photogenerated carrier transfer rate of CoS 2 /Zn 0.5 Cd 0.5 S was better than CoS 2 or Zn 0.5 Cd 0.5 S single catalyst. In this study, the synthesized CoS 2 and Zn 0.5 Cd 0.5 S were both n‐type semiconductors. After close contact, they followed an S‐scheme heterojunction electron transfer mechanism, which not only promoted the separation of their respective holes and electrons, but also retained a stronger reduction potential, thus promoting the reduction of H + protons in photocatalytic experiments. In short, this work provided a new basis for the construction of S‐scheme heterojunction in addition to being used for photocatalytic hydrogen production.