Visible Light-Driven D–A Conjugated Linear Polymer and Its Coating for Dual Highly Efficient Photocatalytic Degradation and Disinfection

Herein, a novel donor–acceptor (D–A) conjugated linear polymeric system, poly[(2,6-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene))-alt-2,5-(3-carboxyl)-thiophene] (PBDT–F–COOH), with outstanding processing ability and its all-organic PBDT–F–COOH coating featuring chemical bonding for combination with polyurethane were prepared. Wide visible spectrum-driven PBDT–F–COOH and PBDT–F–COOH–PU showed dual efficient photocatalytic activities toward degradation and disinfection, mainly attributing to efficient dissociation of excitons and transfer of charge carriers, resulting from the large dipole moment of D–A PBDT–F–COOH. PBDT–F–COOH demonstrated >99.2% inactivation of Staphylococcus aureus (S. aureus) within 1 h and a 7-log decrease in 4 h under visible light irradiation. Additionally, the coating showed the 7-log inactivation of S. aureus in 7 h. These inactivation efficiency results are among those of the best reported D–A conjugated linear polymers. Importantly, PBDT–F–COOH and the PBDT–F–COOH–PU coating both presented satisfactory stability with high photocatalytic activity after recycling runs. This work provides a feasible approach for fabricating nontoxic and highly active organic photocatalysts with wide visible spectra and a large dipole moment via a D–A linear structure design protocol.