Novel Sb2S3-xSex photocathode decorated NiFe-LDH hole blocking layer with enhanced photoelectrochemical performance

Abstract

The alloyed Sb2S3-xSex has attracted widespread attention as a promising light absorbing material in recent years because it has the advantages of both Sb2S3 and Sb2Se3, such as adjustable band gap in the range of 1.1–1.8 eV and good stability. However, expensive selenourea enormously increases its manufacturing cost. In this paper, using Se powder as Se source, high-quality and low-cost Sb2S3-xSex film photoelectrode is successfully prepared by one-step hydrothermal method, and applied to photoelectrochemical (PEC) water splitting. Furthermore, with the help of NiFe-layered double hydroxide (LDH) modification, an increase in photocurrent density from −0.22 mA cm−2 to −1.21 mA cm−2 at 0 VRHE is achieved, and the onset potential is positively shifted by 120 mV. NiFe-LDH significantly improve hydrogen evolution reaction (HER) performance. The relevant characterization can confirm that this is mainly due to the blocking effect of NiFe-LDH on photogenerated holes, promoting effect of Ni2+ on the kinetics of hydrogen evolution reactions, and the strengthening of bulk charge separation efficiency. Undoubtedly, this work opens up a simple and effective way for the development of low-cost, high-efficiency antimony chalcogenides photoelectrodes, and provides new ideas for its excellent application in the field of PEC water splitting.