Recent progress on Z- and S-scheme photocatalysis: mechanistic understanding toward green applications

Photocatalysis has been widely used to address the environmental issues and energy crises that threaten the future of planet Earth. One of the main drawbacks to developing photocatalysts for practical applications is the electron–hole recombination concept, which seriously hinders the photoreaction rate. To resolve this, heterojunctions with different patterns, including Z and S schemes, showed great potential to enhance photoactivity and thus attracted increasing attention. Herein, we concisely reviewed recent progress in various types of such systems, focusing on the mechanistic understanding of clean energy and environmental applications. The principles of constructions based on optoelectronic properties and semiconducting behavior are comprehensively discussed. The advantages and disadvantages of each system are also considered to make a logical conclusion and inspirational perspectives.