Oxygen vacancy boosted photocatalytic decomposition of ciprofloxacin over Bi2MoO6: Oxygen vacancy engineering, biotoxicity evaluation and mechanism study

Xiao Xu; Xing Ding; Xianglong Yang; Pei Wang; Shu Li; Zhexue Lu; Hao Chen

doi:10.1016/j.jhazmat.2018.10.063

Oxygen vacancy boosted photocatalytic decomposition of ciprofloxacin over Bi₂MoO₆: Oxygen vacancy engineering, biotoxicity evaluation and mechanism study

J Hazard Mater. 2019 Feb 15:364:691-699. doi: 10.1016/j.jhazmat.2018.10.063. Epub 2018 Oct 23.

Authors

Xiao Xu¹, Xing Ding², Xianglong Yang², Pei Wang³, Shu Li², Zhexue Lu², Hao Chen⁴

Affiliations

¹ College of Science, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070, China.
² College of Science, Huazhong Agricultural University, Wuhan 430070, China.
³ College of Science, Huazhong Agricultural University, Wuhan 430070, China; State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry & Chemical Engineering, Xiamen University, Xiamen 361005, China.
⁴ College of Science, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: hchenhao@mail.hzau.edu.cn.

PMID: 30399552
DOI: 10.1016/j.jhazmat.2018.10.063

Abstract

Herein, efficient visible light driven photocatalytic degradation of ciprofloxacin was realized over Bi₂MoO₆ with oxygen vacancies (OVs) which can be tunably introduced through a facile solvothermal method via the modulation of tetramethylethylenediamine (TMEDA). The optimal Bi₂MoO₆ with OVs possessed the highest CIP degradation rate of 1.799 mg min^-1 m^-1, about 8.4 times than that of the pristine Bi₂MoO₆. And more than half of CIP was mineralized in only 2 h. The biotoxicity of ciprofloxacin and its byproducts to E. coli K-12 and saccharomyces cerevisiae was thoroughly eliminated after 6 h's photocatalytic treatment. Characterization methods revealed the rich oxygen vacancies in Bi₂MoO₆ not only endowed it with broader visible light absorption and faster transfer of photogenerated carriers, but also provided abundant absorption sites of surface oxygen for efficient molecular oxygen activation. Correspondingly, plentiful active species were produced and participated in the photocatalytic process, thereby efficiently promoting the ciprofloxacin degradation. Based on the HPLC-MS analysis, a possible decomposition pathway of CIP was finally proposed with the first decomposition step of pipetazine ring oxidation and breakage. This work might open up new avenues for superior visible light driven photocatalysts design to deal with pharmaceutical compounds contamination via tunable OVs Engineering.

Keywords: Bi(2)MoO(6); Biotoxicity; Ciprofloxacin; Oxygen vacancies; Photocatalytic degradation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Infective Agents / chemistry*
Anti-Infective Agents / toxicity
Bismuth / chemistry
Catalysis
Ciprofloxacin / chemistry*
Ciprofloxacin / toxicity
Escherichia coli / drug effects
Light*
Molybdenum / chemistry
Molybdenum / radiation effects*
Oxygen / chemistry*
Photolysis
Saccharomyces cerevisiae / drug effects

Substances

Anti-Infective Agents
Bi(2)MoO(6)
Ciprofloxacin
Molybdenum
Oxygen
Bismuth