Efficient degradation of tetracycline in real water systems by metal-free g-C3N4 microsphere through visible-light catalysis and PMS activation synergy

• Published in: Separation and purification technology 2022-01, Vol.280, p.119864, Article 119864
• Main Authors: Shi, Heng, He, Yi, Li, Yubin, He, Teng, Luo, Pingya
• Format: Article
• Language: English
• Subjects: Curved structure; g-C3N4; Microsphere; Peroxymonosulfate; Photocatalysis
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2021.119864

[Display omitted] •Curved C3N4 has higher photocatalysis-PMS activation synergy efficiency than flat C3N4.•The synergy of photocatalysis-PMS activation on MCN mainly contributed to the nonradical pathway.•The curvature of MCN leads to enhanced exciton disassociation and electron-donating property of N atoms.•TC degradation pathway by the vis/MCN/PMS system was identified. In this study, a porous C3N4 microsphere (MCN) with curved structure was fabricated through the preassembly-calcination method, and the visible-light catalysis and PMS activation synergy were studied. Different from the conventional bulk g-C3N4 (CN) with flat geometry, the curvature of the C3N4 microsphere has shown significantly enhanced PMS assisted visible-light catalysis efficiency. Besides, the synergy between PMS activation and photocatalysis on MCN is highly favorable for the application in real water systems. Quenching tests and electron paramagnetic resonance (EPR) analysis revealed that the visible-light catalysis and PMS activation synergy on MCN mainly enhanced the nonradical pathway. DFT calculation indicates that the enhanced performance of MCN than CN is due to the curvature induced spatially uneven distribution of electrons, which facilitates the dissociation of exciton and enhances the electron donation ability of N atoms.