Visible-light-driven 3D Bi5O7I/BiOCl microsphere with enhanced photocatalytic capability: Performance, degradation pathway, antibacterium and mechanism

• Published in: Chemosphere (Oxford) 2022-07, Vol.299, p.134482-134482, Article 134482
• Main Authors: Huang, Jialun, Shen, Jingtao, Zhang, Ganwei, Guo, Yongfu, Zheng, Xinyu
• Format: Article
• Language: English
• Subjects: Antibacterium; Bismuth-based materials; Doxycycline hydrochloride; Heterojunction; Photocatalysis
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.134482

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. [Display omitted] •A 3D microsphere Bi5O7I/BiOCl heterojunction was constructed by precipitation method.•High photodegradation to doxycycline hydrochloride (83%, 90 min) was obtained.•Bi5O7I/BiOCl exhibits super high antibacterial ability for E. coli (99.92%, 90 min).•Bi5O7I/BiOCl has preferable reusability and excellent chemical stability.•Degradation paths and photocatalytic mechanism were provided under visible light.