CdS-sensitized chestnut-like TiO2-based thin films for improved photoelectrochemical performance

In this paper, novel chestnut-like TiO 2 was successfully synthesized by the hydrothermal method. The presence of chestnut-like structure not only increased the density of active sites with a high accessibility, but also facilitated the diffusion of solvent and products. Then, the chestnut-like TiO 2 based thin films on FTO were successfully prepared by the doctor-blade method. Moreover, the thickness of thin films can be adjusted via different repeated times. After that, in order to further improve its photoelectric properties, the adoption of CdS sensitization with different time interval via chemical bath route was studied. Photoelectrochemical (PEC) measurements showed that CdS/TiO 2 photoelectrode under the optimal condition exhibited minimal resistance and the fastest charge transfer rate. The highest photocurrent density can reach 35.1 μ A ⋅ cm − 2 , which is almost 5-fold than that of pure chestnut-like TiO 2 (7.6 μ A ⋅ cm − 2 ) based thin films. The enhanced PEC properties could be ascribed to the improvement of light harvesting and the formation of heterostructure to accelerate the separation of photo-generated electron-hole pairs.