Heterojunction construction on covalent organic frameworks for visible-light-driven H2O2 evolution in ambient air.

Photocatalytic H 2 O 2 production by reducing O 2 has drawn great interest, but most reactions were conducted in pure O 2 which requires extra energy input. Here, TpPa-1 was facilely decorated by ZnIn 2 S 4 nanosheets for H 2 O 2 production in ambient air under visible light. Profiting from the hierarchical heterostructure, efficient visible-light absorption and O 2 capture of ZnIn 2 S 4 /TpPa-1, an H 2 O 2 yield of 516 μmol·L−1 was obtained with 2 h irradiation, which is 3.0 and 3.9 times those of blank TpPa-1 and ZnIn 2 S 4 , respectively. The intimate interface contact between ZnIn 2 S 4 and TpPa-1 also contributes to the performance improvement. It is noted that the photocatalytic H 2 O 2 formation over ZnIn 2 S 4 /TpPa-1 hybrids experienced an indirect reduction of O 2 that ·O 2 - served as the key intermediate. Additionally, the reactions under different atmospheres and ethanol concentrations demonstrate that both O 2 and ethanol play important roles in the efficient evolution of H 2 O 2. This work could enlighten the heterostructure construction and (photo)catalytic H 2 O 2 production based on covalent organic frameworks. [Display omitted] • ZnIn 2 S 4 /TpPa-1 was first constructed for photocatalytic H 2 O 2 evolution in air. • The H 2 O 2 yield is 3 and 3.9 time-enhancement than those of ZnIn 2 S 4 and TpPa-1. • Efficient visible-light absorption and O 2 capture lead to the high activity. • The H 2 O 2 formation over ZnIn 2 S 4 /TpPa-1 undergoes an indirect reduction of O 2. [ABSTRACT FROM AUTHOR]