Nature-Inspired Pyrylium Cation-Based Vinylene-Linked Two-Dimensional Covalent Organic Framework for Efficient Sunlight-Driven Water Purification

Sunlight-driven photocatalytic water purification for the removal of persistent organic compounds and microorganisms has been widely regarded as a promising technology due to the low energy consumption and environmental friendliness; however, it calls for efficient and sustainable photocatalysts. Pyrylium cation is a photoactive component of many naturally occurring dyes in fruits, flowers, and leaves. Herein, we report the synthesis of a novel pyrylium cation contained vinylene-linked two-dimensional covalent organic framework (v-2D-COF-O1) via aldol-type polycondensation. The resultant v-2D-COF-O1 has a narrow band gap (1.15 eV) and wide-range light absorption up to similar to 920 nm. More importantly, the v-2D-COF-O1 can activate molecular oxygen to generate highly reactive oxygen species including superoxide (center dot O2-) and hydroxyl radicals (center dot OH) under simulated sunlight (AM 1.5 G), which leads to remarkable photocatalytic activities in both organic waste decomposition and water disinfection. These results suggest the potential of v-2D-COFs as high-performance photocatalysts for water purification.

Automated summary

A novel pyrylium cation contained two-dimensional covalent organic framework (v-2D-COF-O1) with narrow band gap and wide-range light absorption was synthesized. Under simulated sunlight, v-2D-COF-O1 can activate molecular oxygen and generate highly reactive oxygen species, leading to efficient organic waste decomposition and water disinfection. This suggests the potential of v-2D-COFs as high-performance photocatalysts for water purification.