Hierarchically porous CsPbBr3@HZIF-8 heterojunctions for high-performance photocatalytic degradation of antibiotics in high-salinity wastewater

Abstract

The photocatalytic degradation of tetracycline hydrochloride (TCH) under high salinity poses a significant challenge due to the inhibitory effect of coexisting ions on reactive oxygen species in wastewater. Herein, a series of hierarchically porous Z-scheme CsPbBr₃@HZIF-8 heterojunctions were synthesized by a sequential deposition method. Benefiting from the stable hierarchical pore structure of HZIF-8 and the excellent optoelectronic properties of CsPbBr₃, the hierarchical pore Z-scheme heterojunction CsPbBr₃@HZIF-8 not only facilitates the mass transfer and enrichment of pollutants but also accelerates the transfer of carriers between HZIF-8 and CsPbBr₃, leading to enhanced generation of reactive oxygen species. Moreover, CsPbBr₃ serves as a photosensitizer for energy transfer, generating singlet oxygen (¹O₂) with higher resistance to ion interference. As a result, the 4%-CsPbBr₃@HZIF-8 achieved the highest visible light degradation efficiency of TCH (94% in 40 min), surpassing those of most reported CsPbBr₃-based photocatalysts. The catalytic system consistently degrades contaminants in deionized water, high ion concentrations, and real water matrices. The photocatalytic reaction mechanisms, involving charge carrier transfer, reactive species generation, and TCH degradation intermediate products, are thoroughly investigated.