Molecular structure design of conjugated microporous poly(dibenzo[b,d]thiophene 5,5-dioxide) for optimized photocatalytic NO removal

Abstract

Conjugated microporous polymers with high BET surface areas and a tunable bandgap are promising candidates for photocatalytic NO removal in the solid–gas phase reaction system. Herein, we report that three conjugated microporous poly(dibenzo[b,d]thiophene 5,5-dioxide) (B-DT-1,3,5; B-DT-1,2,4; B-DT-1,2,4,5) consisting of alternating electron-rich and electron-deficient units with ethynyl linker have been synthesized, and optical bandgaps varied from 2.29 eV to 2.79 eV by adjusting the position and number of CC connected to the 3D center benzene. Combined with intrinsic merits including facile tunable bandgap and high BET surface areas, the synthesized CMP(B-DT) proved to be good photocatalysts for photocatalytic NO removal. The NO removal efficiency of B-DT-1,3,5 reached up to 56% with good stability. Active species scavenger experiments and other characterizations indicated that the superior photocatalytic NO removal ability of B-DT-1,3,5 may arise from the synergistic effect of stronger hole oxidation ability, greater amounts of O2− and 1O2, and higher BET surface area. Thus, our proof-of-concept design of conjugated microporous polymers was used for a highly efficient photocatalytic NO removal in the solid-gas phase.