In-situ construction of novel Sb₂(S,Se)₃/CdSe S-scheme heterojunction with enhanced photoelectrochemical performance

Abstract

Antimony selenosulfide (Sb2(S,Se)3) was considered to have great potential for photoelectrochemical (PEC) water splitting applications due to its excellent chemical stability, good light absorption, abundant reserves and non-toxicity. However, Sb2(S,Se)3 faces some limitations in the field of PEC, such as the serious recombination problem of photogenerated carriers. Therefore effectively restraining its deep-level defects is the crucial for enhancing its photoelectrochemical properties. In this paper, We successfully fabricated Sb2(S,Se)3/CdSe S-scheme heterojunction via one-step hydrothermal method, which improves its solar absorption capacity, facilitates efficient carrier separation. And, Sb2(S,Se)3/CdSe S-scheme heterojunction can suppress the adverse effects of deep-level defects on the PEC performance of Sb2(S,Se)3. Under simulated solar irradiation, the light current density can reach 4.02 mA cm2 (33.5 times that of monomeric Sb2(S,Se)3) at 1.23 VRHE, accompanied by low initial voltage and extremely high surface charge injection efficiency. This study is of great significance for the application of Sb2(S,Se)3 in the PEC field.