Enhanced Photoelectrochemical Performance of 2D Bi2O3/TiO2 Heterostructure Film by Bi2S3 Surface Modification and Broadband Photodetector Application

Photoelectrochemical devices have garnered extensive research attention in the field of smart and multifunctional photoelectronics, owing to their lightweight nature, eco-friendliness, and cost-effective manufacturing processes. In this work, Bi2S3/Bi2O3/TiO2heterojunction film was successfully fabricated and functioned as the photoelectrode of photoelectrochemical devices. The designed Bi2S3/Bi2O3/TiO2photoelectrochemical photodetector possesses a broad light detection spectrum ranging from 400 to 900 nm and impressive self-powered characteristics. At 0 V bias, the device exhibits an on/off current ratio of approximately 1.3 × 106. It achieves a commendable detectivity of 5.7 × 1013Jones as subjected to a 0.8 V bias potential, outperforming both bare TiO2and Bi2O3/TiO2photoelectrochemical devices. Moreover, the Bi2S3/Bi2O3/TiO2photoelectrode film shows great promise in pollutant decomposition, achieving nearly 97.7% degradation efficiency within 60 min. The appropriate band energy alignment and the presence of an internal electric field at the interface of the Bi2S3/Bi2O3/TiO2film serve as a potent driving force for the separation and transport of photogenerated carriers. These findings suggest that the Bi2S3/Bi2O3/TiO2heterojunction film could be a viable candidate as a photoelectrode material for the development of high-performance photoelectrochemical optoelectronic devices.