Three-in-one approach to fabricate a porous porphyrin-heptazine polymer for highly efficient visible light photocatalysis†

Abstract

Efficient metal-free heterogeneous photocatalysts, using visible light from the sun, continue to be a design challenge for use in chemical synthesis. Compared to metal-free photocatalysts involving a fundamental redox process, multi-dimensional photocatalytic systems with enhanced performance are limited. In this contribution, we demonstrated a general three-in-one approach to construct a donor–acceptor (D–A)-based porous organic polymer via connecting the most applied porphyrin with heptazine into a porous framework structure. Herein, a cooperative excitation process for O₂ activation was established, where porous organic polymers can not only generate ¹O₂ under light irradiation via a triplet state, but also capture O₂ and reduce it to O₂˙⁻. This synergistic effect dramatically improved the photocatalytic performance, as exemplified in the context of several important aerobic oxidative transformations, including sulfur mustard simulant degradation, oxidative coupling of primary amine molecules, and oxidative conversion of sulfides. Our work, therefore, paves a new way for the development of highly efficient heterogeneous photocatalysts.