title: Photocatalytic oxidation of trace carbamazepine in aqueous solution by visible-light-driven Znln2S4: Performance and mechanism.
abstract: In this work, visible-light-driven Znln2S4photocatalyst (band gap 1.98 eV, absorption wavelength 300-600 nm) was synthesized by a facile hydrothermal method for photocatalytic degradation of trace pharmaceutical carbamazepine (CBZ) in aqueous solution, and characterized by UV-Vis diffusive reflectance spectroscopy, BET, SEM and XRD, respectively. It demonstrated that a complete degradation of CBZ was achieved with an optimal Znln2S4dosage of 30 mg/L under a 100 W iodine-gallium lamp irradiation of 20 min, which afforded the reaction rate constant and half-life being respectively 10.44 times higher and 1/8 less than that obtained by a direct photolysis without Znln2S4photocatalyst. A negligible influence of initial solution pH on photocatalytic degradation of CBZ was confirmed under the given pH range of 5.0-9.0. The degradation efficiency of CBZ was slightly decreased from 91% to 84% after five consecutive cycles. Hydroxy radical (·OH) plays an important role in CBZ degradation accompanying a synergistic effect of photogenerated hole (h+) and O2-active species during reaction. Further, 44 intermediates were detected by LCMS-IT-TOF technique and tentative degrading pathways were proposed on the basis of the experimental results.
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China. Electronic address: bolongli@xauat.edu.cn.
authors.forename: Longli
authors.initials: L
authors.lastname: Bo
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Kebo
authors.initials: K
authors.lastname: He
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Na
authors.initials: N
authors.lastname: Tan
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Feng
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Jiadong
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road No. 13, Xi'an, 710055, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D002220:Carbamazepine / Q000737:chemistry*; D002384:Catalysis; D006801:Humans; D008027:Light; D010084:Oxidation-Reduction; D010782:Photolysis; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002220:Carbamazepine
keywords: Carbamazepine; Degradation pathway; Intermediates; Photocatalysis; Znln(2)S(4)