CdS/TpPa-Cl2/MXene hybrids with chlorine-mediated MXenes and CdS for photocatalytic H2O2 production in ambient air and pure water

Specific intermolecular interactions are the keys to constructing benign interfacial compatibility, which determines the activities of hybrid photocatalysts. In this study, CdS/TpPa-Cl 2 /MXene hybrids were compactly developed through the mediation of chlorine groups in TpPa-Cl 2 with MXenes and CdS. Owing to the formation of the Schottky junction between TpPa-Cl 2 and MXene and the heterojunction between TpPa-Cl 2 and CdS, as well as the close interfacial contacts among them, the photogenerated electron–hole pairs are effectively separated, which ultimately results in efficient photocatalytic activities. For visible-light-driven H 2 O 2 production in ambient air and pure water, CdS/TpPa-Cl 2 /MXene hybrids could achieve a high H 2 O 2 yield of 1005 μmol·L –1 , which is 2.5, 9.7 and 6.5 times greater than those of pure TpPa-Cl 2 , MXene and CdS, respectively. The mechanism investigation revealed that an indirect O 2 reduction pathway with ·O 2 – as an intermediate occurred for H 2 O 2 production over the CdS/TpPa-Cl 2 /MXene composites, and this two-electron O 2 reduction process was manifested as the primary way. This study provides insight into the construction of multi-component composite photocatalysts with high efficiency on the basis of covalent organic frameworks.