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.

Automated summary

Three porous conjugated polymers based on 1,3,5-triphenylbenzene were designed for photochemical reduction of CO2 in simulated flue gas. By tuning the properties of the comonomers, these polymers exhibited high surface areas and CO2 selectivity, as well as broad visible light absorbance.