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

Abstract

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 μmol 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.