Bismuth sulfide decorated TiO2 arrays heterojunction assembly for enhanced photoelectrochemical performance

Hetero-junction photo-anode exhibits unique optical and electrical properties which are depended on their composition, morphology and structure. In this work, TiO2/Bi2S3 heterojunction photoanode was successfully prepared. Firstly, the TiO2 nanorod arrays were prepared by hydrothermal method under different reaction time, and then the Bi2S3 has been deposited with successive ionic layer adsorption and reaction method (SILAR). The array length and radius nanorods of TiO2 have important influence on their photoelectric properties. The deposition time was optimized according to the photoelectric performance. The Bi2S3 nanomaterials on TiO2 nanoarrays is not obvious. The existence of Bi2S3 on TiO2 was confirmed by XPS and HRTEM. This is mainly due to the fact of that Bi2S3 prepared by SILAR method is very small and relatively dispersed. The photoelectric properties of TiO2/Bi2S3 photoanode can be enhanced by increasing the reaction concentration. The photoelectric response of TiO2/Bi2S3 shows firstly increase and then decreases with the increasing of cationic solution concentration. When the reaction concentration is 10 mmol/L, the photocurrent density reached the maximum (0.060 mA/cm(2)). It is anticipated that the present work can provide a simple and rapid preparation technology for the development and use of high-performance photoanode composites based on titanium dioxide.