Sb₂S₃surface modification for improved photoelectrochemical water splitting performance of BiVO₄photoanode

A fabrication of Sb2S3 layer as surface modification on pyramidal BiVO4 film is realized to improve photoelectrochemical (PEC) performance of BiVO4 photoanode. The Sb2S3-modified BiVO4 film exhibits an increased photocurrent density of 1.1 mA/cm2 at 1.23 V versus reversible hydrogen electrode and a negative shift of onset potential. Further, the negative shift of flat band potential demonstrates that the role of Sb2S3 surface modification is to suppress surface recombination, and thus increased surface separation and hole transfer efficiency are also achieved for the Sb2S3-modified BiVO4 photoanode. Accordingly, the Sb2S3 surface modification enhances surface water oxidation kinetics for the BiVO4 photoanode, resulting in improved PEC performance. These findings inspire further application of Sb2S3 into a PEC water splitting system.