Visible light photocatalytic degradation of tetracycline with porous Ag/graphite carbon nitride plasmonic composite: Degradation pathways and mechanism

Weicheng Xu; Shufeng Lai; Suresh C Pillai; Wei Chu; Yun Hu; Xueding Jiang; Mingli Fu; Xiaolian Wu; Fuhua Li; Hailong Wang

doi:10.1016/j.jcis.2020.04.038

Visible light photocatalytic degradation of tetracycline with porous Ag/graphite carbon nitride plasmonic composite: Degradation pathways and mechanism

J Colloid Interface Sci. 2020 Aug 15:574:110-121. doi: 10.1016/j.jcis.2020.04.038. Epub 2020 Apr 9.

Authors

Weicheng Xu¹, Shufeng Lai², Suresh C Pillai³, Wei Chu⁴, Yun Hu⁵, Xueding Jiang⁶, Mingli Fu⁵, Xiaolian Wu⁷, Fuhua Li⁷, Hailong Wang⁸

Affiliations

¹ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China. Electronic address: weichengxu@fosu.edu.cn.
² School of Transportation and Civil Engineering, Foshan University, Foshan 528000, China.
³ Nanotechnology and Bio-engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology Sligo, Sligo, Ireland.
⁴ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
⁵ School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
⁶ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China. Electronic address: jiangxueding@fosu.edu.cn.
⁷ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China.
⁸ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, China.

PMID: 32311534
DOI: 10.1016/j.jcis.2020.04.038

Abstract

Ag/g-C₃N₄ plasmonic photocatalysts with porous structure (Ag/PCN) were successfully synthesized via a thermal exfoliation strategy and photo-reduction method. Owing to the combined merits of porous structure and surface plasmon resonance effect of silver nanoparticles, the Ag/PCN catalysts exhibited excellent photocatalytic performance for the degradation of antibiotic agents. With the optimal Ag loading, the Ag/PCN-2 catalyst exhibited the optimal catalytic activity for TC degradation under visible light, which shows about 11.8 times enhancement in the photocatalytic removal efficiency as compared to pure g-C₃N₄, respectively. This phenomenon can be attributed to the increased specific surface area, broadened visible light absorption and improved charge separation. The radical quenching results confirmed that h⁺ and O₂^- radicals were the major active species during removal of TC. The degradation of TC is increased with the increment of Ag/PCN-2 catalysts, and the optimum catalyst was found to be 1.67 g/L. The hindering effect of selected of anions (Cl^-, CO₃^-, H₂PO₄^-) was found to follow the order H₂PO₄^- > CO₃^- > Cl^-. Ag/PCN-2 sample also possessed high stability after six cycles of reuses. Furthermore, the possible degradation pathways of TC and photocatalytic mechanism over Ag/PCN-2 were proposed in detail.

Keywords: Ag; Antibiotic; Degradation pathway; G-C(3)N(4); Photocatalysis; Porous structure.