Construction of CdS/ZnO/TiO2 ternary heterojunction with hierarchical structure as photo-anode for enhancing photo-electrochemical performance

Composition and microstructure expert a significant impact on the photoelectric properties of the photo-anode. In this work, CdS/TiO2 2 and CdS/ZnO/TiO2 2 heterojunction materials were prepared using a simple and low-cost hydrothermal method. Their microstructure, crystallinity, elemental presence state and photoelectron-chemical performance of the heterojunction materials were investigated by SEM, XRD, XPS and Electrochemical workstation. The hydrothermal growth time of CdS has a significant impact on the structure and performance of heterojunctions. As the CdS deposition time increase, the photocurrent density of CdS/TiO2 2 shows a trend of first increasing and then decreasing. We optimized the process parameters of CdS/TiO2 , 2 , and the optimal growth time for CdS is 6h. The transient photocurrent density value of CdS/TiO2 2 heterojunction is 0.15 mA/cm2. 2 . Depositing ZnO onto TiO2 2 to construct a hierarchical ZnO/TiO2 2 heterojunction can improve light absorption and accelerate carrier separation efficiency. The photoelectric performance of CdS/ZnO/TiO2 2 was compared with CdS/TiO2 2 and pure TiO2. 2 . The photocurrent density of CdS/ZnO/TiO2 2 is 1.5 mA/cm2 , 2 , which is significantly larger than that of pure TiO2 2 and CdS/TiO2. 2 . This is due to the formation of a heterojunction between TiO2 2 and ZnO, which promotes the separation of carriers and ultimately improves the photoelectric performance of the CdS/ZnO/TiO2 2 ternary heterojunction. The fabricated CdS/ZnO/TiO2 2 heterojunction showed high photocurrent, which indicated a new candidate for photoelectric device.