1,3,5-Triphenylbenzene Based Porous Conjugated Polymers for Highly Efficient Photoreduction of Low-Concentration CO2 in the Gas-Phase System

Herein, three 1,3,5-triphenylbenzene based porous conjugated polymers (PCPs) are designed for photochemical reduction of CO2 in simulated flue gas in the mild gas-solid reaction system. By tuning the nature of the comonomers, the PCPs present high surface areas, high CO2/N-2 selectivity, and broad visible light absorptions with bandgaps of 1.81-2.07 eV. At 1 bar and 273 K, the CO2 uptake capacity of PCPs is enhanced from 1.28 to 2.18 mmol g(-1), with an increase in CO2 adsorption heat from 21.8 to 28.3 KJ mol(-1). In the presence of gaseous water, SO-TPB demonstrates the highest CO production rate of 40.12 mu mol h(-1) g(-1) and nearly 100% product selectivity without using organic sacrificial reagent and additional cocatalyst (>420 nm). Moreover, SO-TPB can be recovered while well retaining the photocatalytic activity and reused at least five runs, indicating good recyclability.