Constructing a novel CuS/Cu2S Z-scheme heterojunction for highly-efficiency NIR light-driven antibacterial activity

Constructing a Z-scheme photocatalytic system offers great advantages for boosting photocatalytic performance due to its effective charge carrier transfer and strong redox capability. Herein, Cu 2 S/CuS nanosheets heterojunction were prepared by a facile one-pot solvothermal method. CuS/Cu 2 S Z-scheme heterojunction realized rapid bacteria-killing under near-infrared (NIR) irradiation. The optimized CuS/Cu 2 S (CuS/Cu 2 S-1) achieved 99 % antibacterial efficiency against Escherichia coli ( E. coli ) within 10 min NIR irradiation. Owing to the optimization of CuS/Cu 2 S-1 Z-scheme heterojunction, the efficient interfacial charge separation was realized, thereby resulting in a high yield of reactive oxygen species. Moreover, the heterojunction exhibited locally a higher temperature under NIR irradiation, favorable for eradicating bacteria. In addition, radical scavenging tests and ESR spectra results showed that ⋅O 2 – , ⋅OH and 1 O 2 were main active species responsible for sterilization. Under the synergy of photocatalytic and photothermal effects, the membrane structure of bacteria was severely damaged in CuS/Cu 2 S-1 system. This study not only offers a reliable approach for photothermocatalytic inactivation, but also affords the bases for the development of Z-scheme heterojunction aimed at designing highly efficient photocatalysts.