Ultrathin Bi2WO6 nanosheets loaded g-C3N4 quantum dots: A direct Z-scheme photocatalyst with enhanced photocatalytic activity towards degradation of organic pollutants under wide spectrum light irradiation

Mingjuan Zhang; Yi Zhang; Lin Tang; Guangming Zeng; Jiajia Wang; Yuan Zhu; Chengyang Feng; Yaocheng Deng; Wenze He

doi:10.1016/j.jcis.2018.12.112

Ultrathin Bi₂WO₆ nanosheets loaded g-C₃N₄ quantum dots: A direct Z-scheme photocatalyst with enhanced photocatalytic activity towards degradation of organic pollutants under wide spectrum light irradiation

J Colloid Interface Sci. 2019 Mar 15:539:654-664. doi: 10.1016/j.jcis.2018.12.112. Epub 2019 Jan 2.

Authors

Mingjuan Zhang¹, Yi Zhang², Lin Tang³, Guangming Zeng⁴, Jiajia Wang¹, Yuan Zhu¹, Chengyang Feng¹, Yaocheng Deng⁵, Wenze He¹

Affiliations

¹ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
² College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China. Electronic address: zyi@hnu.edu.cn.
³ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China. Electronic address: tanglin@hnu.edu.cn.
⁴ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China. Electronic address: zgming@hnu.edu.cn.
⁵ College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China.

PMID: 30639983
DOI: 10.1016/j.jcis.2018.12.112

Abstract

A novel ultrathin Bi₂WO₆ nanosheets loaded g-C₃N₄ quantum dots (CNQDs/BWO) photocatalyst was successfully fabricated, and used to catalyze two representative organic pollutants, rhodamine B (RhB) and tetracycline (TC) under wide spectrum light irradiation. The degradation experiments showed that CNQDs/BWO exhibited enhanced photocatalytic activities towards degradation of organic pollutants. Under visible light irradiation, the 5% CNQDs/BWO exhibited the best degradation efficiency with 87% and 92.51% removal of TC and RhB within 60 min, respectively. And under near-infrared (NIR) light, the 5% CNQDs/BWO still showed the best performance, its degradation efficiency to TC were ∼2 times than pure BWO. The upconversion behaviors of CNQDs might contribute to the enhanced photocatalysis. According to similar degradation trend, it is inferred that the catalytic mechanism in NIR light is consistent with that in visible light. The enhanced photocatalytic activity of CNQDs/BWO under wide spectrum light irradiation can be ascribed to a Z-scheme mechanism based on the calculated the lowest unoccupied molecular orbital (LUMO) of CNQDs and CB position of BWO, the free radical quenching experiment, and ESR characterization results. The composites have prominent light absorption, high stability and excellent photocatalysis efficiency, which would be used as a promising strategy for organic pollutants degradation.

Keywords: Bi(2)WO(6); Near infrared light; Visible light; Z-scheme mechanism; g-C(3)N(4) quantum dots.