Abstract

With the development of industrialization, global environmental pollution and energy crisis are becoming increasingly serious. Organic pollutants pose a serious health threat to human beings and other organisms. The removal of organic pollutants in the environment has become a global challenge. The photocatalytic technology has been widely used in the degradation of organic pollutants with its characteristics of simple process, high efficiency, thorough degradation and no secondary pollution. However, the single photocatalyst represented by TiO₂ has the disadvantages of low light utilization rate and high recombination rate of photocarriers. Building heterojunction is considered one of the most effective methods to enhance the photocatalytic performance of a single photocatalyst, which can improve the separation efficiency of photocarriers and the utilization of visible light. The classical heterojunction can be divided into four different cases: type I, type II, p-n heterojunctions and Z-scheme junction. In this paper, the recent progress in the treatment of organic pollution by heterostructure photocatalysts is summarized, and the mechanism of heterostructure photocatalysts for the treatment of organic pollutants is reviewed. It is expected that this paper can deepen the understanding of heterostructure photocatalysts and provide guidance for high efficient photocatalytic degradation of organic pollutants in the future.

Keywords: Heterojunction, mechanism of degradation, organic pollutants, photocarrier transport, photocatalysis, photogenerated electron-hole pairs.

Graphical Abstract