Oxygen vacancy-mediated sandwich-structural TiO2-x /ultrathin g-C3N4/TiO2-x direct Z-scheme heterojunction visible-light-driven photocatalyst for efficient removal of high toxic tetracycline antibiotics

Jiaxin Ni; Wei Wang; Dongmei Liu; Qi Zhu; Jialin Jia; Jiayu Tian; Zheyu Li; Xin Wang; Zipeng Xing

doi:10.1016/j.jhazmat.2020.124432

Oxygen vacancy-mediated sandwich-structural TiO_2-x /ultrathin g-C₃N₄/TiO_2-x direct Z-scheme heterojunction visible-light-driven photocatalyst for efficient removal of high toxic tetracycline antibiotics

J Hazard Mater. 2021 Apr 15:408:124432. doi: 10.1016/j.jhazmat.2020.124432. Epub 2020 Oct 31.

Authors

Jiaxin Ni¹, Wei Wang¹, Dongmei Liu², Qi Zhu³, Jialin Jia¹, Jiayu Tian⁴, Zheyu Li¹, Xin Wang¹, Zipeng Xing⁵

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
² State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China. Electronic address: mei18@hit.edu.cn.
³ Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China.
⁴ School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin 300401, China.
⁵ Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China. Electronic address: xingzipeng@hlju.edu.cn.

PMID: 33189474
DOI: 10.1016/j.jhazmat.2020.124432

Abstract

A surface defect sandwich-structural TiO_2-x/ultrathin g-C₃N₄/TiO_2-x direct Z-scheme heterojunction photocatalyst is successfully constructed. The results manifest the existence of oxygen vacancies, sandwich structure and direct Z-scheme heterojunction. Noticeably, TiO_2-x/ultrathin g-C₃N₄/TiO_2-x efficiently eliminates high toxic tetracycline hydrochloride by means of·O₂^-, h⁺ and·OH, whose removal rate is 87.7% during 90 min and the pseudo-first-order rate constant reaches up to 31.7 min^-1 × 10^-3. The extraordinary performance can be attributed to the special 3D structure, Z-scheme heterojunction expediting charge transfer and promoting the generation of active species, meanwhile the oxygen vacancies enhancing the spatial separation of photo-induced carriers. Moreover, various environmental factors are systematically explored by statistics. SO₄^2-, NH₃-N and pH exhibit an obvious impact on removal rate. Meanwhile, TiO_2-x/ultrathin g-C₃N₄/TiO_2-x could also effectually remove tetracycline hydrochloride from complex actual-wastewater and exhibit high stability. Besides, the photocatalytic mechanism and degradation path of tetracycline hydrochloride are also elucidated.

Keywords: Oxygen vacancies; Sandwich structure; Tetracycline hydrochloride; Visible-light photocatalysis; Z-scheme heterojunction.

Publication types

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

MeSH terms

Anti-Bacterial Agents
Catalysis
Light*
Oxygen*
Tetracycline

Substances

Anti-Bacterial Agents
Tetracycline
Oxygen