LAUSR

A novel visible light-driven photocatalyst (represented as Mn-CdS/ZCISe/CIS/TiO2) for the inactivation of Escherichia coli (E. coli) was prepared with TiO2 nanowires as support and CuInS2 (CIS), ZnCuInSe (ZCISe) quantum dots (QDs), and Mn-doped CdS (Mn-CdS) nanoparticles (NPs) as sensitizers. The use of CIS, ZCISe QDs and Mn-CdS NPs extends the light harvest region to visible light. The photoelectric conversion efficiency was consequently improved with a photocurrent density of 12.5 mA/cm2, about 60 times that of the pure TiO2 nanowires. The bactericidal efficiency of the photocatalyst was evaluated on the inactivation of E. coli, 96% bacteria in 50 mL 105 colony forming units (CFU)/mL solution were killed within 50 min. Besides the high efficiency, the composite has good stability and satisfactory recycling performance. The antibacterial mechanism was also studied by employing photoluminescence and scavengers of different reactive species, revealing that it was the photo-generated holes to kill the bacterium.