Ultrafast carrier transport in ultrafine porous 2D polymers for the highly selective photocatalytic reduction of CO2 to CH4

The generation of high-calorific-value hydrocarbon fuels is still limited by poor photoinduced carrier transport in organic polymers. Herein, 2D polymers with different porous structures were synthesized by adopting a good-solvent/poor-solvent control strategy, and the photocatalytic CO2 reduction behavior was further compared. It was verified that the ultrafine porous structure in the 2D polymer (D1M4-PC) is responsible for the selective formation of CH4. The CH4 yield of the D1M4-PC sample reached 6733 mu mol g(-1), and the CH4 selectivity was near 100%. Experiments and theoretical calculations show that the ultrafine porous structure can provide an extremely short carrier transport distance and has accessible active sites, which enables the photoinduced carrier migration to the trapped CO2 molecules rapidly, enabling high selectivity photocatalytic CO2 conversion. This work offers a promising strategy for designing polymers for the conversion of CO2 into high-calorific-value hydrocarbon fuels with high selectivity and activity.