Synthesis of ZnO Co-doped Ph-g-C₃N₄ for enhanced photocatalytic organic pollutants removal under visible light

ABSTRACT

The paper deals with the synthesis of a binary ZnO/Ph-g-C₃N₄ nanocomposite, a highly efficient visible light active catalyst for the photodegradation of organic pollutants in aqueous suspension by single-step calcination and combustion process. The synthesised materials have been characterised using different techniques such as X-ray diffraction, UV-Vis, FTIR, SEM-EDX, and TEM. The UV-Vis DRS analysis indicates 20–30 nm red-shift and a decrease in bandgap from 3.1 to 2.7 eV on doping ZnO with Ph-g-C₃N_4. The photocatalytic activity of the prepared nanocomposites was tested by studying the degradation of two different chromophoric dyes, rhodamine B (RhB) and methyl orange (MO) and a drug derivative, Paracetamol. The composite, 0.05% ZnO/Ph-g-C₃N_4, displayed the best activity for the degradation of both dyes and the drug. The trapping and quenching studies indicate that both hydroxyl and superoxide radical anions are responsible for the degradation of pollutants under investigation. The higher photocatalytic activity of the prepared samples could be attributed to the generation of heterojunction between the Ph-g-C₃N₄ and ZnO, which is the response for improved light absorption and efficient separation of the photo-excited electron and hole pair.

KEYWORDS:

• Photocatalysis
• ZnO/Ph-g-C₃N₄ nanocomposite
• visible light active catalyst
• photodegradation of dye/drug/organic pollutants

Acknowledgments

The authors are thankful for the financial support to research projects from the Science and Engineering Research Board, Government of India (CRG/2019/001370), and acknowledge DST and UGC, for research supports (DRS II, PURSE & FIST) to the Department of Chemistry AMU, Aligarh. Murad Z. A. Warshagha is thankful to the Indian council for cultural relations (ICCR), for the financial support of his Ph.D. Program.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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Additional information

Funding

This work was supported by the Aligarh Muslim University & science and engineering research board.