Efficient photocatalytic water disinfection by a novel BP/BiOBr S-scheme heterojunction photocatalyst

With the ever-growing threat posed by pathogenic microorganisms, the development of high-performance photocatalysts for energy-efficient and rapid water disinfection is urgently required. In this study, an S-scheme heterojunction involving black phosphorus (BP) and bismuth oxybromide (BiOBr) is designed by a facile exfoliation strategy. The BP/BiOBr with 0.75% of BP (0.75 %BP/BiOBr) exhibits an outstanding photocatalytic disinfection activity, with the total 7 log killing of E. coli cells in only 7.5 min under visible-light illumination, which is 2 times higher than that of pure BiOBr. And the similar performance was observed for the tap water and river water under real sunlight. The enhanced disinfection efficiency of BP/BiOBr arises from the high yield of the ·O2− and ·OH resulting from the formation of S-scheme heterojunction. Then the ·O2− and ·OH damaged the cell membrane of the bacterial, leading to their death finally. This research sheds lights on the design and application of S-scheme heterojunction photocatalysts in water disinfection.