The surface asymmetric site regulation of carbon nitride oxide enabling peroxymonosulfate activation for degrading tetracycline

Abstract

Peroxymonosulfate (PMS) activation by the carbonaceous-based materials for degrading antibiotics is a recent emerging hotspot in water environment restoration. Herein, a triazine carbon material is prepared by urea thermal condensation follwed by water-mediated oxidation. The optimized triazine carbon material (CNOR15) can degrade around 100 % of tetracycline within 6 mins, thus pseudo-first-order kinetic constant (kobs) enhances approximately 49 folds compared to pristine carbon material. Experiments and characterizations demonstrate non-radical reactive species of 1O2 plays a crucial role in CNOR15/PMS system to eliminate tetracycline, in which performs at an asymmetric C = O site on the edge of triazine motief. Electron paramagnetic resonance and trapping tests comfirm the novel mechanism of electron conduction from sp/sp2-hybrdized triazine to C = O prompting PMS decomposition for 1O2 generation. Ex-situ argon sputtering XPS technology solidly unveils a underlysing linear corelation between catalysis activity and content of carbonyl-constructed assymetric sites. In addition, membranoid CNOR15/PVDF removes ca. 90 % tetracycline at a rate of 100 mL·min−1 in a continuous flow-cell device, exhibiting a promising application in the practical wastewater purification. Our work emphasized a significance of asymmetric site regulation of carbonaceous materials towards PMS activation for environmental remediation.