Synergistic effect of ZnO QDs and Sn4+ ions to control anatase-rutile phase of three-dimensional ordered hollow sphere TiO2 with enhanced photodegradation and hydrogen evolution

Abstract

A novel three-dimensional ordered hollow spherical Sn4+ doped TiO2 material with ZnO quantum dot sensitization (ZnO QDs@Sn-TiO2) was synthesized by a simple colloidal template method. The characterization results indicate that the crystal phase of the prepared composite could be controlled by modifying the loading of ZnO QDs under the synergistic action of ZnO QDs and Sn4+ while maintaining the favorable three-dimensional ordered hollow sphere structure. Based on diffuse reflectance and fluorescence spectroscopy, ZnO QDs provide multiple migration pathways for photogenerated carriers, effectively inhibiting the recombination of photogenerated electron–hole pairs. And the photocatalytic experiments show that the photocatalyst ZnO QDs@Sn-TiO2 has significantly improved photocatalytic performance than pure TiO2. Simultaneously, the optimized results show that 2.0 ZnO QDs@Sn-TiO2 has the best degradation rate and photocatalytic activity. In summary, this work provides a new approach for the synthesis of multi-morphological mixed phase TiO2 photocatalysts for photocatalytic applications.