Visible-light-driven photocatalytic degradation of sulfamethazine by surface engineering of carbon nitride：Properties, degradation pathway and mechanisms

Chengyun Zhou; Zhuotong Zeng; Guangming Zeng; Danlian Huang; Rong Xiao; Min Cheng; Chen Zhang; Weiping Xiong; Cui Lai; Yang Yang; Wenjun Wang; Huan Yi; Bisheng Li

doi:10.1016/j.jhazmat.2019.120815

Visible-light-driven photocatalytic degradation of sulfamethazine by surface engineering of carbon nitride：Properties, degradation pathway and mechanisms

J Hazard Mater. 2019 Dec 15:380:120815. doi: 10.1016/j.jhazmat.2019.120815. Epub 2019 Jun 29.

Authors

Chengyun Zhou¹, Zhuotong Zeng², Guangming Zeng³, Danlian Huang⁴, Rong Xiao⁵, Min Cheng¹, Chen Zhang¹, Weiping Xiong¹, Cui Lai¹, Yang Yang¹, Wenjun Wang¹, Huan Yi¹, Bisheng Li¹

Affiliations

¹ College of Environmental Science and Engineering, Hunan University and and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
² Department of Dermatology, Second Xiangya Hospital, Central South University, Changsha, 410011, PR China.
³ College of Environmental Science and Engineering, Hunan University and and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China. Electronic address: zgming@hnu.edu.cn.
⁴ College of Environmental Science and Engineering, Hunan University and and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China. Electronic address: huangdanlian@hnu.edu.cn.
⁵ Department of Dermatology, Second Xiangya Hospital, Central South University, Changsha, 410011, PR China. Electronic address: xiaorong65@csu.edu.cn.

PMID: 31295684
DOI: 10.1016/j.jhazmat.2019.120815

Abstract

Polymeric carbon nitride semiconductor has been explored as emerging metal-free photocatalyst for solving the energy shortage and environmental issues. However, the efficiency of carbon nitride is still not satisfying. Herein, a facile copolymerization between L-cysteine and dicyandiamide has been applied to forming the modified carbon nitride photocatalysts. The photocatalytic performance was evaluated through degrading sulfamethazine under visible light illumination. The ameliorative structure and tuned energy band result in visible-light adsorption enhancement. In addition, nitrogen vacancies offer more sites to adsorbing molecular oxygen, thereby facilitating the transfer of electrons from carbon nitride to the surface adsorbed oxygen. As a result, the degradation rate of optimized modified carbon nitride sample for sulfamethazine was 0.1062 min^-1, which was almost 12 times than that of carbon nitride (0.0086 min^-1). Superoxide radicals and holes were mainly responsible for the sulfamethazine photodegradation by modified carbon nitride. Two reaction intermediates/products were observed and identified by high performance liquid chromatography-mass spectrometer, and a possible reaction pathway was proposed. This study provides new insights into the design of highly efficient photocatalyst for other organic pollutants degradation.

Keywords: Carbon nitride; L-cysteine; Nitrogen vacancy; Photocatalysis; Sulfamethazine degradation.

Publication types

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