Why the cooperation of radical and non-radical pathways in PMS system leads to a higher efficiency than a single pathway in tetracycline degradation

• Published in: Journal of hazardous materials Vol. 424; no. Pt A; p. 127247
• Main Authors: Xiao, Zi-Jie, Feng, Xiao-Chi, Shi, Hong-Tao, Zhou, Bai-Qin, Wang, Wen-Qian, Ren, Nan-Qi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2022
• Subjects: Co3O4@rGO/PMS; Cobalt; Cooperation of oxidation pathway; Density functional theory; Multiple active species; Oxides; Peroxides; Tetracycline; Cooperation of oxidation pathway; Density functional theory; Multiple active species; Co3O4@rGO/PMS; Tetracycline; CoO@rGO/PMS
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127247

[Display omitted] Current research focused on developing multiple active species in peroxymonosulfate (PMS) system to degrade contaminants, but deepening concern lacks over why cooperation of those active species facilitated a faster degradation. Here, we employed Co3O4, rGO and Co3O4@rGO composite to activate PMS for tetracycline (TC) degradation, and detected crucial factors toward highest performance of Co3O4@rGO/PMS system. Batch experiments exhibited a satisfactory TC degradation efficiency under Co3O4@rGO/PMS, complete degraded 50 mg/L TC within 20 min. Analytical tests discovered that radical active species generated by Co3O4/PMS and non-radical species by rGO/PMS were successfully co-existed in Co3O4@rGO/PMS system, significantly improving the performance of TC removal. Subsequently, a combination of density functional theory (DFT) calculation and intermediates analysis revealed that, in Co3O4@rGO/PMS system, the cooperation rather than independent effect of radical and non-radical active species expanded TC degradation pathways, enhancing the degradation performance. Furthermore, decent adaptability, stability, and recyclability toward affecting factors variation of Co3O4@rGO/PMS demonstrated it as a potent and economical system to degrade TC. Overall, this study developed a novel Co3O4@rGO/PMS system with a cooperative oxidation pathway for highly efficient TC removal, and managed to clarify why this oxidation pathway achieved high efficiency through a combination of theoretical and experimental method. •Cooperative oxidation pathways were developed in Co3O4@rGO/PMS system.•The advantages of Co3O4@rGO/PMS system were verified by calculations and experiments.•Optimal Co3O4@rGO showed an excellent catalytic performance.•Co3O4@rGO/PMS system has a satisfactory adaptability, stability, and recyclability.