Visible light excited graphitic carbon nitride for efficient degradation of thiamethoxam: Removal efficiency, factors effect and reaction mechanism study. Issue 4 (August 2021)

• Record Type: Journal Article
• Authors: Wang, Yongchang; Deng, Yaocheng; Gong, Daoxin; Yang, Lihua; Li, Ling; Zhou, Zhanpeng; Xiong, Sheng; Tang, Rongdi; Zheng, Jiangfu
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 4(2021)
• Publication Date: 2021-08
• Subjects: Thiamethoxam THM -- g-C3N4 Graphic carbon nitride -- HA Humic acid -- FA Fulvic acid -- ESR Electron spin resonance -- O2- superoxide radical -- OH Holes -- h+ Humic acid. -- HPLC High performance liquid chromatography -- IPA Isopropanol -- EDTA-2Na Ethylenediaminetetraacetic acid disodium salt -- BQ Benzoquinone -- SEM Scanning electron microscopy -- TEM Transmission electron microscopy -- XRD X-ray diffractometer -- FTIR Fourier transform infrared spectroscopy -- XPS X-ray photoelectron spectroscopy; Visible light irradiation -- Neonicotinoid pesticides -- Thiamethoxam -- G-C3N4 nanosheets -- Photocatalytic degradation; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105739
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this decade, photocatalytic degradation of organic contaminants has attracted great attentions. In this study, we used graphic carbon nitride (g-C3 N4 ) nanosheets as the photocatalyst for the degradation of thiamethoxam (THM). The properties of g-C3 N4 nanosheets have been fully characterized by the analysis techniques. The experiments results shown that under the optimum condition, 91.3% of THM degradation efficiency can be reached in the presence of g-C3 N4 nanosheets within 60 min under visible light irradiation. Take the realistic application into consideration and to fully investigate the reaction process, the influence of reaction parameters, including the dosage of g-C3 N4 nanosheets, initial THM concentration, and initial solution pH value, co-existence ions, humic acid (HA) and fulvic acid (FA) have been systematically studied and discussed. Results demonstrated that weak acidity and neutral condition is benefit for THM decomposition, and Ca 2+ and Mg 2+ present enhanced inhibition effect than Na + for THM removal. Meanwhile, PO4 3- and CO3 2- show strong inhibition effect, but HA and FA performed weak inhibitory effect. The trapping experiments and electron spin resonance (ESR) measurement demonstrated that superoxide radical (O2 - ), hydroxyl radical (OH) and holes (h + ) are all generated during the reaction process. There are all participated in the THM decomposition process and O2 - plays the major role on it. The results obtained in this study indicated that metal free g-C3 N4 present great photocatalytic activity and stability for THM removal and owns great potential in the application of actual agricultural environment. Graphical Abstract: ga1 Highlights: Visible light degradation of thiamethoxam based on g-C3N4 has been systematically studied. Superoxide radical, hydroxyl radical and holes are all contributed to thiamethoxam decomposition. Environmental factors study demonstrates g-C3N4 owns great stability for thiamethoxam removal. g-C3N4 has a strong practical significance for thiamethoxam wastewater remediation.