New insight into rapid removal of refractory pollutants via efficient charge transfer under visible light

Abstract

The widespread use of personal care products poses significant risks to both ecosystems and human health. The construction of photocatalysts with the advantages of enhanced visible light absorption, efficient charge separation and high stability is important for the degradation of persistent environmental pollutants. Herein, we have prepared two D-A heterojunction organic semiconductor photocatalysts: PV-BDTC1:IDTCN/Biochar and PV-BDTC2:IDTCN/Biochar by a simple design method that can be widely applied. Under visible light irradiation, PV-BDTC2:IDTCN/Biochar showed better removal ability for indomethacin, with reaction rate constants 14.7 and 5.1 times higher than those of PV-BDTC2:IDTCN and Biochar, respectively. This is attributed to the construction of a heterojunction between the donor and the acceptor, which expands the light absorption range and promotes the separation of photogenerated carriers, thereby giving the material the ability to produce a large number of reactive oxygen species during the photocatalytic reaction. In addition, Biochar well ensures the stability of D-A heterojunction films under long-term operating conditions. This work highlight the potential of natural biomaterials in constructing effective D-A heterojunction organic photocatalysts/adsorbents for combatting water pollution.