Azobenzene-equipped Covalent triazine polymers for Visible-Light-Driven photocatalytic reduction of CO2 to CH4

Covalent triazine polymers, as large π conjugated, highly porous, nitrogen riched organic semiconductors, can play a key role in tackling the fuel energy crisis and global warming issues. However, their development in photocatalytic CO 2 reduction is still rare. More effective strategies to enhance CO 2 reduction activity need to be explored. Herein, different amounts of azobenzene pendants functionalized CTPs: Azo-CTP 0 , Azo-CTP 1 , Azo-mCTP 1 and Azo-CTP 2 , were fabricated for photocatalytic CO 2 reduction with Pd loaded. Among them, Azo-mCTP 1 displayed the highest CO 2 uptake capacity up to 48.2 cm 3 g −1 (2.15 mmol g −1 ) at 273 K, and the highest CH 4 evolution rate in the water system, with selectivity highly up to 97 %. Apart from that, the azobenzene functionalization of Azo-CTP 0 could significantly boost the CO 2 reduction efficiency by 4 times. Therefore, this study provides a potentially general approach for accurately modifying organic semiconductors to enhance photocatalytic performance.