Rational design of kaolinite-based photocatalytic materials for environment decontamination

Semiconductor-based photocatalysts play vital roles in environmental treatment owing to their advanced oxidation processes under ultraviolet light irradiationul. However, the practical application of traditional photocatalysts is limited by the narrow absorption spectrum of sunlight, low electron transport rates, and recycling difficulties. The kaolinite-based photocatalytic nanocomposites prepared by loading semiconductors onto a kaolinite matrix have a significant effect on enhancing the adsorption capacity and utilization of ultraviolet and visible light. This review first summarizes the mineralogical characteristics of kaolinite, the preparation of common kaolinite-based photocatalytic materials, and the photocatalytic reaction mechanism. On this basis, the application of kaolinite-based photocatalytic materials for environmental purification is described in detail. Moreover, this review highlights the shortcomings in the field of photocatalysis and the new development direction of synthesizing efficient, environmentally friendly, and reusable nanocomposite photocatalysts by coupling naturally existing clay minerals with catalysts. This review aims to provide a summary of recent progress in environmental decontamination based on kaolinite-based photocatalytic materials and some useful guidelines for future development.