Studies on the preparation and optical properties of ZnO hollow nanosphere/ZnCo2S4 nanoparticle composite photocatalyst

A new binary composite photocatalyst consisting of ZnO hollow nanospheres and ZnCo 2 S 4 nanoparticles was prepared by a two-step method. Carbon nanospheres as templates for the preparation of ZnO hollow nanospheres were synthesized by a hydrothermal method . Using X-ray photoelectron spectroscopy (XPS), ultraviolet visible diffuse reflectance spectroscopy (UV vis DRS) and Mott Schottky curve measurements, the regulated band structure of the composite was determined, and then the type-II carrier transfer mechanism in the composite was identified. The effect of the mass ratio of ZnCo 2 S 4 to ZnO on the photocatalytic performance of the composite was investigated. With the increase in the mass ratio of ZnCo 2 S 4 to ZnO, the photocatalytic performance of the composite first increases and then decreases, and the composite sample with a mass ratio of 30% shows the best performance. Furthermore, the introduction of oxygen vacancy (V O ) defects into ZnO hollow nanospheres not only improves the photocatalytic performance of the composite but also greatly improves photocorrosion resistance. Therefore, the newly discovered ZnCo 2 S 4 /ZnO composite photocatalyst has potential practical applications.