title: Photocatalytic degradation of clofibric acid by g-C3N4/P25 composites under simulated sunlight irradiation: The significant effects of reactive species.
abstract: Pharmaceutically emerging micropollutants have become an environmental concern in recent years. In the present paper, the reactive species (RSs)-induced degradation mechanism of clofibric acid (CA) was investigated using a newly sunlight-driven g-C3N4/P25 photocatalyst. A very low g-C3N4content of 8.0 weight percent resulted in a 3.36 and a 2.29 times faster reaction rate for CA photodegradation than for pristine g-C3N4and P25, respectively. Electron spin resonance and quenching experiments demonstrated the participation of HO, h+, e-,1O2and O2·-in the photocatalytic system, and the contribution rates were calculated to 73.3%, 15.3%, 5.1%, 6.7% and 33.1%, respectively. According to the pulse radiolysis measurements and the competitive kinetics approaches, the bimolecular reaction rate constants for HO, e-, and1O2with CA were (8.47 ± 0.33) × 109M-1s-1, (6.41 ± 0.48) × 109M-1s-1and (6.6 ± 0.37) × 106M-1s-1, respectively. RSs were found to significantly influence the degradation of CA, and the degradation pathways occurred primarily via e-reduction, HO addition and1O2attack reactions on the basis of mass spectrometry and theoretical calculations.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Fengliang
authors.initials: F
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Qianxin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Yuehan
authors.initials: Y
authors.lastname: Su
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Lingzhi
authors.initials: L
authors.lastname: Shen
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yao
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Zhi-Feng
authors.initials: ZF
authors.lastname: Chen
authors.affiliation: Faculty of Environmental and Biological Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Lv
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China. Electronic address: liugg615@163.com.
authors.forename: Guoguang
authors.initials: G
authors.lastname: Liu
mesh_terms: D000924:Anticholesteremic Agents / Q000737:chemistry; D002995:Clofibric Acid / Q000737:chemistry*; D000960:Hypolipidemic Agents / Q000737:chemistry; D007700:Kinetics; D010782:Photolysis; D013472:Sunlight; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000924:Anticholesteremic Agents; D000960:Hypolipidemic Agents; D014874:Water Pollutants, Chemical; D002995:Clofibric Acid
keywords: Clofibric acid; Pathways; Photocatalysis; Reactive species; g-C(3)N(4)/P25