Photocatalytic mechanism of tourmaline/ZnO composites

Abstract

Tourmaline/ZnO composite material was prepared by one-step hydrothermal method. The structure, morphology and optical properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray fluorescence spectroscopy and UV-Vis DRS. Under visible light irradiation, the photocatalytic performance of tourmaline/ZnO composite was studied using acid fuchsin as a degradation product. The kinetic model was used to simulate the degradation process of acid fuchsin. The results show that the addition of tourmaline does not affect the morphology of ZnO petals, but has a great influence on its photocatalytic properties. With the increase of the content of tourmaline, the photocatalytic performance first increases and then decreases. When the content of tourmaline is 5%(mass fraction), the recombination probability of photogenerated electron-hole decreases, the forbidden band width decreases, the concentration of hydroxyl radical (·OH) increases and the photocatalytic efficiency reaches the maximum 96.62%, ZnO and tourmaline/ZnO catalytic degra-dation of composites follows a first-order kinetic model.

Keywords

• tourmaline/zno
• photocatalysis
• hydroxyl radical(·oh)
• first-order kinetics