ZnFe2O4-based composites for photocatalytic degradation of antibiotics: An overview of synthesis method, modification, factors affecting degradation and toxicity assessment

The overuse of antibiotics has resulted in serious water pollution, posing a great threat to human health. Photocatalysis is considered as a sustainable, effective, and economical strategy for antibiotic elimination. ZnFe 2 O 4 -based photocatalysts have presented excellent photocatalytic activity and stability, and their separation from water is facile due to their magnetic properties. In this work, different preparation methods of ZnFe 2 O 4 -based photocatalysts are reviewed. Besides, various strategies for improving photocatalytic activity of ZnFe 2 O 4 -based photocatalysts are summarized in detail, along with the analysis of affecting factors on antibiotic photodegradation efficiency. Meanwhile, the reaction pathway and toxicity of intermediates during antibiotic photodegradation by ZnFe 2 O 4 -based photocatalysts are analyzed. The degrading intermediates presented weak antimicrobial activity and low or almost non-toxic toxicity. Furthermore, challenges and upcoming research requirements of ZnFe 2 O 4 -based photocatalysts are addressed. This review aims to offer a referable resource for the development of ZnFe 2 O 4 -based photocatalysts for the elimination of antibiotics from wastewater.