Fabrication of In2O3/In2S3 heterostructures for enhanced photoelectrochemical performance

Constructing core/shell heterojunction has always been an effective strategy for photoelectrochemical (PEC) water splitting owing to special morphology characterization and band structure. Herein, we synthesized a series of In₂O₃/In₂S₃ core/shell structure photoanodes via a simple two-step hydrothermal method to improve the PEC performance of In₂O₃. Various methods were employed to investigate the influence of sulfurization time on the morphologies, microstructures, photoelectrochemical properties and band structures of the as-prepared photoanodes. The results indicated that the In₂O₃/In₂S₃-5 possessed stronger visible light absorption, faster charge transfer rate and higher electron carrier density, which resulted in an excellent PEC performance. Under visible light irradiation, the photocurrent density of the In₂O₃/In₂S₃-5 photoanode reached 0.53 mA cm⁻² at 1.23 V vs RHE in 1 M NaOH solution, which was about twice as high as that of the pristine In₂O₃. Furthermore, the onset potential of the In₂O₃/In₂S₃-5 photoanode had an obvious negative shift (~200 mV) when compared to the pure In₂O₃ nanorod photoanode.