Boosting the photoreduction uranium activity for donor–acceptor–acceptor type conjugated microporous polymers by statistical copolymerization

Conjugated microporous polymers (CMPs) have attracted much attention due to their environmental friendliness, high conjugation and design ability, but the development of efficient CMPs photocatalysts for the photoreduction of uranium remains a challenge due to the monolithic nature of polymer synthesis and the mismatch of band gaps. Here, the two acceptors dibenzothiophene-S,S-dioxide (SO) and benzothiadiazole (TH) with different electron-absorbing capacities were chosen, with the acceptor II TH having the greater electron-absorbing capacity, and then a series of donor-acceptor-acceptor (D-A-A) CMPs photocatalysts were innovatively designed by adjusting the ratio between the electron donor benzene (B) and the electron acceptor TH by means of statistical copolymerization. As well as photocatalytic characterization, the effect of different ratios of CMPs on its performance was explored. The results show that the band gap of D-A-A polymers can be regularly regulated by statistical copolymerization, and the PBSOTH-2 polymer with a feed ratio of 1.0: 3.0: 1.5 achieves 99.2% uranium removal when methanol is the sacrificial agent. This work has established a database for the photocatalytic reduction of uranium by D-A-A terpolymer by statistical copolymerization, which provides some ideas for the design of catalysts for the efficient reduction of uranium.