Insight into Fe-O-Bi electron migration channel in MIL-53(Fe)/Bi4O5I2 Z-scheme heterojunction for efficient photocatalytic decontamination

Yanyu Song; Xianbo Sun; Long D Nghiem; Jun Duan; Wen Liu; Yongdi Liu; Zhengqing Cai

doi:10.1016/j.jcis.2024.04.096

Insight into Fe-O-Bi electron migration channel in MIL-53(Fe)/Bi₄O₅I₂ Z-scheme heterojunction for efficient photocatalytic decontamination

J Colloid Interface Sci. 2024 Aug:667:321-337. doi: 10.1016/j.jcis.2024.04.096. Epub 2024 Apr 15.

Authors

Yanyu Song¹, Xianbo Sun¹, Long D Nghiem², Jun Duan³, Wen Liu⁴, Yongdi Liu⁵, Zhengqing Cai⁶

Affiliations

¹ National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai 200237, China.
² Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia.
³ Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA.
⁴ The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
⁵ National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai 200237, China. Electronic address: ydliu@ecust.edu.cn.
⁶ National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai 200237, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200237, China. Electronic address: caizhengqing@ecust.edu.cn.

PMID: 38640652
DOI: 10.1016/j.jcis.2024.04.096

Abstract

Building a heterojunction is a fascinating option to guarantee sufficient carrier separation and transfer efficiency, but the mechanism of charge migration at the heterojunction interface has not been thoroughly studied. Herein, MIL-53(Fe)/Bi₄O₅I₂ photocatalyst with a Z-scheme heterojunction structure is constructed, which achieves efficient photocatalytic decontamination under solar light. Driven by the newly-built internal electric field (IEF), the formation of Fe-O-Bi electron migration channel allows for rapid separation and transfer of charge carriers at the heterojunction interface, confirmed by the material characterization and density functional theory (DFT) calculation. The narrower band gap and improved visible light response also contribute to the enhanced photocatalytic activity of composite materials. With levofloxacin as the target pollutant, the optimal MIL-53(Fe)/Bi₄O₅I₂ achieves complete removal of pollutant within 150 min, the photocatalysis rate of which is ca. 4.4 and 26.0 times that of pure Bi₄O₅I₂ and MIL-53(Fe), respectively. Simultaneously, the optimal composite material exhibits satisfactory photodegradation of seven fluoroquinolones, and the photocatalysis rates are as follows: lomefloxacin > ciprofloxacin > enrofloxacin > norfloxacin > pefloxacin > levofloxacin > marbofloxacin. DFT calculations reveal a positive relationship between degradation rate and Fukui index (ƒ⁰) of main carbon atoms in seven fluoroquinolones. This study sheds light on the existence of electron migration channels at Z-scheme heterojunction interface to ensure sufficient photoinduced carrier transfer, and reveals the influence of pollutant structure on photolysis rate.

Keywords: Electronic migration channel; Fluoroquinolones; Photocatalysis; Structure-rate relationship; Z-scheme heterojunction.