Covalent Microporous Polymer Nanosheets for Efficient Photocatalytic CO2 Conversion with H2O

It is still a challenging target to achieve photocatalytic CO2 conversion to valuable chemicals with H2O as an electron donor. Herein, 2D imide-based covalent organic polymer nanosheets (CoPcPDA-CMP NSs), which integrate cobalt phthalocyanine (CoPc) moiety for reduction half-reaction and 3,4,9,10-perylenetetracarboxylic diimide moiety for oxidation half-reaction, are constructed as a Z-scheme artificial photosynthesis system to complete the overall CO2 reduction reaction. Owing to the outstanding light absorption capacity, charge separation efficiency, and electronic conductivity, CoPcPDA-CMP NSs exhibit excellent photocatalytic activity to reduce CO2 to CO using H2O as a sacrificial agent with a CO production rate of 14.27 mu mol g(-1) h(-1) and a CO selectivity of 92%, which is competitive to the state-of-the-art visible-light-driven organic photocatalysts towards the overall CO2 reduction reaction. According to a series of spectroscopy experiments, the authors also verify the photoexcited electron transfer processes in the CoPcPDA-CMP NSs photocatalytic system, confirming the Z-scheme photocatalytic mechanism. The present results should be helpful for fabricating high-performance organic photocatalysts for CO2 conversion.

Automated summary

The study presents the construction of a Z-scheme artificial photosynthesis system using 2D imide-based covalent organic polymer nanosheets (CoPcPDA-CMP NSs) for photocatalytic CO2 reduction. The CoPcPDA-CMP NSs demonstrated excellent photocatalytic activity in reducing CO2 to CO using H2O as an electron donor. The spectroscopy experiments confirmed the Z-scheme photocatalytic mechanism.