Constructing a highly efficient CuS/Cu9S5 heterojunction with boosted interfacial charge transfer for near-infrared photocatalytic disinfection

Heterojunction engineering has emerged as a promising strategy for facilitating photogenerated charge carriers utilization ability and improving photocatalytic activity. Herein, a novel heterojunction of CuS/Cu9S5 hybrid was designed for near-infrared-driven (NIR) photocatalytic inactivation. Benefiting from the heterojunction structure and the internal electric field of CuS/Cu9S5 hybrid, the efficiency of photogenerated charge carriers separation and transfer can be greatly boosted, thus increasing the yields of reactive oxygen species (⋅O2−, ⋅OH and 1O2). The reactive oxygen species generation in both strains induced by CuS/Cu9S5 was 11.34-fold (Escherichia coli) and 12.51-fold (Bacillus subtilis), compared to the control. In addition, CuS/Cu9S5 enabled generate local high temperature (53 ℃) to assist inactivation Consequently, CuS/Cu9S5 heterojunction exhibited 99.99% sterilization rates toward Escherichia coli and Bacillus subtilis within 10 min NIR irradiation at a relatively low concentration of 25 µg/mL, which were significantly higher than those of pure CuS and Cu9S5 under the same condition, respectively. This work provides a new method of designing high-performance heterojunction photocatalysts for efficient inactivation.