 The S-scheme strategy has been used to enhance the photocatalytic performance of carbon nitride CN by introducing various functional groups into CN. These functional groups can improve the electronic structure of CN, increase the efficiency of charge separation, and reduce the recombination of electron, whole pairs. Additionally, the S-scheme strategy can also be applied to CN-based photocatalysts for hydrogen evolution and CO2 reduction. This article was offered by Yao Weixiao, Su Tian, Yun Hua Chen, and others.