Design of hollow mesoporous TiO2@BiOBr/Bi4O5Br2 type-II/Z-scheme tandem heterojunctions under confinement effect: Improved space charge separation and enhanced visible-light photocatalytic performance

Jie Yang; Haifei Zhou; Chen Chen; Wang Cao; Caiyun Jiang; Yuping Wang

doi:10.1016/j.jcis.2022.03.026

Design of hollow mesoporous TiO₂@BiOBr/Bi₄O₅Br₂ type-II/Z-scheme tandem heterojunctions under confinement effect: Improved space charge separation and enhanced visible-light photocatalytic performance

J Colloid Interface Sci. 2022 Jul:617:341-352. doi: 10.1016/j.jcis.2022.03.026. Epub 2022 Mar 8.

Authors

Jie Yang¹, Haifei Zhou¹, Chen Chen¹, Wang Cao¹, Caiyun Jiang², Yuping Wang³

Affiliations

¹ School of Chemistry and Material Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, PR China.
² Jiangsu Engineering Research and Development Center of Food Safety, Department of Health, Jiangsu Vocational Institute of Commerce, Jiangsu 211168, PR China.
³ School of Chemistry and Material Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, Nanjing University of Science and Technology, Nanjing 210094, PR China. Electronic address: wangyuping@njnu.edu.cn.

PMID: 35279569
DOI: 10.1016/j.jcis.2022.03.026

Abstract

The new type of hollow mesoporous TiO₂@BiOBr/Bi₄O₅Br₂ type-II/Z-scheme tandem heterojunction is synthesized using MIL-125(Ti) as the precursor based on the confinement effect caused by the outward shrinkage induced by the interface. Among them, the BiOBr shell is an indispensable component of forming a cavity during the pyrolysis of MIL-125(Ti). Not only that, BiOBr is partially converted into Bi-rich Bi₄O₅Br₂ at high temperature, and the remaining BiOBr acts as a bridge to connect TiO₂ and Bi₄O₅Br₂ to construct a type-II/Z-scheme tandem heterojunction. This new type of hollow mesoporous tandem heterojunction shows excellent degradation efficiency (95%) for 10 mg/L ciprofloxacin (CIP) within 40 min, with a rate constant (K) of 0.05930 min^-1. The Fukui index is used to determine the attack site of CIP, and the possible degradation pathway is proposed through LC-MS analysis. The results of the culture of Vibrio qinghaiensis-Q67 showed that ciprofloxacin and its intermediate products have biological toxicity, and the toxicity is reduced with the progress of photodegradation. This method of synthesizing novel hollow mesoporous TiO₂@BiOBr/Bi₄O₅Br₂ type-II/Z-scheme tandem heterojunctions based on the confinement effect will provide a new idea for other use of MOF to synthesize hollow and high-efficiency heterojunctions.

Keywords: Bismuth-rich; Confinement effect; MOF pyrolysis; Photodegradation; Tandem heterojunction.

MeSH terms

Bismuth*
Catalysis
Ciprofloxacin*
Titanium

Substances

titanium dioxide
Ciprofloxacin
Titanium
bismuth oxybromide
Bismuth