The change of phase states in situ of the charge carriers toward the high H2 performance of Cu2O/TiO2 nanocomposite via p-n heterojunction
Le Thi Ngoc Tu, Ton Nu Quynh Trang, Vu Thi Hanh Thu
The charge carriers in the heterojunction structure are playing a significant role in the photocatalytic toward hydrogen evolution reaction. Herein, we focus on analyzing the change of the influence of annealing treatment upon the structural properties and the photocatalytic hydrogen performance of Cu2O/TiO2 heterojunction structure. Our results show that the eﬃciency and the rate of photocatalytic hydrogen generation over the Cu2O/TiO2 samples were found to be higher than TiO2 owing to the occurrence of the charge carrier transport via p-n heterojunction between Cu2O and TiO2 that can be suppressed the recombination rate of photogenerated electron-hole pairs. Moreover, after being annealed the various temperatures from 300°C-700°C, the obtained H2 evolution of Cu-based photocatalyst significantly affected due to the presence of transition phase from anatase to rutile in the crystal structure, leading to the change the redox potential in heterojunction. It is noticed that the highest hydrogen of the CuO/TiO2-500 photocatalyst with an apparent quantum yield of about 10.8% was obtained compared with others under the same conditions. These results will provide insight for clean energy evolution in the future based on the p-n heterojunction structure.