In situ loading of polyurethane/negative ion powder composite film with visible-light-responsive Ag3PO4@AgBr particles for photocatalytic and antibacterial applications

A multifunctional Ag3PO4@AgBr-polyurethane/negative ion powder (Ag3PO4@AgBr-PU/NI) composite film is obtained by a combination of nonsolvent induced phase separation (NIPS) and an impregnation-precipitation. ion exchange method. The PU/NI composite film has an asymmetric porous structure and is used as a support to provide sites for the in situ loading of Ag3PO4@AgBr particles. Various analytical techniques are applied to explore the characteristic properties of the films. The photocatalytic activity and recyclability of the films are assessed by the decomposition of methyl orange (MO) in recycling processes under visible light irradiation. The Ag3PO4@AgBr-PU/NI composite film exhibits higher photocatalytic activity than the Ag3PO4-PU/NI and AgBr-PU/NI composite films. Moreover, up to approximately 85% of the photocatalytic efficiency of the Ag3PO4@AgBr-PU/NI composite film is retained after three-cycle testing. A possible photocatalytic mechanism for the Ag3PO4@AgBr-PU/NI film is proposed based on active species trapping experiments and a theoretical analysis. The composite films display a broad-spectrum antibacterial property against Gram-negative E. coli and Gram-positive S. aureus. This work may provide a simple pathway to construct a highly efficient polyurethane composite film reactor for organic pollutants degradation and bacterial inactivation.