Novel ZIF-8/ZnS hollow polyhedral heterostructures derived from ZIF-8 with enhanced photocatalytic activity for degradation of aflatoxin B1

Abstract

Mycotoxins, formed in lots of foods during the production, processing and transportation processes, are the secondary metabolites of Fusarium genus, Penicillium and Aspergillus. Aflatoxin B1 (AFB1) is considered as one of the most dangerous mycotoxins for human and animals due to its strong carcinogenicity and hepatotoxic effects. Hence, degradation of AFB1 completely or reduction of AFB1 to a low degree content has caused much attentions. In this paper, novel ZIF-8/ZnS hollow polyhedral heterostructures were successfully synthesized by sulphurizing ZIF-8 via solvothermal method. The synthesized samples were used as catalysts for AFB1 degradation under UV light irradiation. All as-synthesized samples were analyzed by XRD, SEM, BET, UV–vis, ESR and so on. The results show that parts of ZIF-8 can be sulphurized by TAA to synthesize ZnS and the ZIF-8 particles were etched to form the hollow structure. The sulphurizing degree of ZIF-8 has great influence on the photocatalytic activity of ZIF-8/ZnS. Compared with ZIF-8/ZnS (50) and ZIF-8/ZnS (150), ZIF-8/ZnS (100) exhibited the best photocatalytic activity and could degrade 98.6 ​% of AFB1. Except that, the reactive species of ZIF-8/ZnS (100) were confirmed to be ·OH and ·O2−. This strategy of coupling MOFs with semiconductor provides a facile method to synthesize for catalyst with enhanced photocatalytic activity for degradation of food pollutants produced by aflatoxins. KeyworksAflatoxin B1, ZIF-8/ZnS, photocatalytic activity, reactive species.