Surface anchoring of nickel sulfide clusters as active sites and cocatalysts for photocatalytic antibiotic degradation and bacterial inactivation

Abstract

Achieving photocatalytic antibiotic degradation and bacterial inactivation with high efficiency remains a challenging mission to originate a clean environment. In this work, ultra-small NiS clusters were in-situ grew on photoactive ZnIn2S4 nanoflower supports to form a NiS/ZnIn2S4 heterojunction, in which a strong and surface-limited binding was formed between the NiS clusters and ZnIn2S4 supports. The in-situ formed NiS clusters not only appeased interfacial charge transfer resistance of the heterojunction but also eventuated a strong built-in electric field, resulting a fast electron migration from ZnIn2S4 to NiS clusters functioned as cocatalyst and active sites to boost the separation efficiency of photogenerated carriers. As a result, the optimal 2NiS/ZnIn2S4 heterojunction expressed a higher photocatalytic Escherichia inactivation activity (99.23 % for 3 h) and a raised antibiotic degradation performance, including tetracycline (60 % for 20 min), ofloxacin (62 % for 20 min), oxytetracycline (63 % for 20 min) compared to that of pure ZnIn2S4 (39.14 % for Escherichia inactivation and 44 % for tetracycline degradation). This work furnishes a great promise to develop inorganic clusters coupled photocatalysts for light-driven environmental application.