It is well known that both of the separation efficiency of photogenerated carriers and the response capability to visible light remarkably affect the photocatalytic performance. In the present work, a 3D microsphere of Bi5O7I/BiOCl heterojunction catalyst was synthetised. The synergy of Bi5O7I and BiOCl not only significantly enhances the transfer rate and separation efficiency of carriers, but also heightens light absorption capacity. As-prepared Bi5O7I/BiOCl (40 wt% BiOCl) has a higher degradation efficiency on doxycycline hydrochloride (DC) (90 min, 83.0%) and super high inhibition rate (90 min, 99.92%) on Escherichia coli under visible light, compared to the two monomers. Pollutants DC is finally decomposed into CO2, H2O and small molecule intermediates by generated h+, •OH and •O2-. The effects of reactive radicals follow the order of •OH radicals > h+ radicals ≫ •O2- and e- radicals. The possible structures of intermediates and four possible degradation pathways involved were also discussed. In addition, As-synthetised Bi5O7I/BiOCl has preferable reusability and excellent chemical stability. Biological toxicity experiments also verify that Bi5O7I/BiOCl is a green and environmentally friendly composite material. This strategy provides a green, low-toxic way for the application of traditional type II heterojunction in the fields of environmental remediation and photocatalysis.
Keywords: Antibacterium; Bismuth-based materials; Doxycycline hydrochloride; Heterojunction; Photocatalysis.
Copyright © 2022 Elsevier Ltd. All rights reserved.