Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO₃/TiO₂/ZnO for the Photodegradation of Methylene Blue

Abstract

Designing new materials that can be used to treat environmental pollutants is one of the prime focuses of chemical science. Here, an unprecedented photocatalytic material with high activity of catechol sensitized ZnTiO3/TiO2/ZnO hollow microspheres was synthesized by hydrothermal method. The structure and properties of the composite photocatalyst were analyzed by various testing methods. The photocatalytic activity was evaluated by using methylene blue (MB) as the target degradation substance. The results demonstrated that catechol (CA) sensitized ZnTiO3/TiO2/ZnO photocatalyst is a hollow microsphere with a diameter of 1–1.5 mm, the CA molecules are covalently bonded to the ZnTiO3/TiO2/ZnO surface, and the composite photocatalyst has good light absorption and carrier separation performance. Under the condition of irradiation for 90 min, the degradation rate of the composite photocatalyst for MB was higher than that of ZnTiO3/TiO2/ZnO. When the loading amount of CA was 0.6 wt%, the degradation rate of CA/ZnTiO3/TiO2/ZnO for MB was as high as 98.28 %, and the reaction rate constant was up to 4.35×10−2 min−1. A reasonable mechanism of photocatalytic degradation of pollutants by catechol as sensitizer on ZnTiO3/TiO2/ZnO was proposed. This study provides a theoretical reference for efficient photodegradation of pollutants in the environment.