Integrating Enrichment, Reduction And Oxidation Sites in One System for Artificial Photosynthetic Diluted CO 2 Reduction.

Artificial photosynthetic diluted CO 2 reduction directly driven by natural sunlight is a challenging but promising way to realize carbon-resources recycling utilization. Herein, a three-in-one photocatalytic system of CO 2 enrichment, CO 2 reduction and H 2 O oxidation sites was designed for diluted CO 2 reduction. A Zn-Salen-based covalent organic framework (Zn-S-COF) with oxidation and reductive sites was synthesized, then ionic liquids (ILs) were loaded into the pores. As a result, [Emim]BF 4 @Zn-S-COF shows a visible-light-driven CO 2 -to-CO conversion rate of 105.88 μmol·g -1 ·h -1 under diluted CO 2 (15%) atmosphere, even superior than most photocatalysts in high concentrations CO 2 . Moreover, natural sunlight driven diluted CO 2 reduction rate also reached 126.51 μmol·g -1 in 5 h. Further experiments and theoretical calculations reveal that the triazine ring in Zn-S-COF promotes the activity of H 2 O oxidation and CO 2 reduction sites, and the loaded ILs provide an enriched CO 2 atmosphere, realizing the efficient photocatalytic activity in diluted CO 2 reduction. This article is protected by copyright. All rights reserved.