In situ grown single-atom cobalt on carbon nanofibers for efficient adsorptive removal of antibiotics: Performance and mechanisms understanding

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.499, p.156594, Article 156594
• Main Authors: Xia, Simeng, Chen, Fan, Shi, Zhou, Deng, Lin, Georgi, Anett, Zhang, Haojie
• Format: Article
• Language: English
• Subjects: Adsorption mechanisms; Carbon nanofibers; DFT calculations; Single-atom cobalt; Sulfadiazine and roxarsone
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156594

[Display omitted] •Single-atom cobalt incorporated carbon nanofibers (CoSA-CNF) was synthesized.•CoSA-CNF showed high adsorption capacity for sulfadiazine (413.16 mg/g) and roxarsone (338.42 mg/g).•The Co-N3 configuration was more favorable to adsorb organic pollutants than the Co-N4 configuration.•CoSA-CNF could be rapidly regenerated in the presence of PMS.•CoSA-CNF membrane exhibited a robust durability for SDZ and ROX removal. Single-atom cobalt on carbon materials have emerged as a highly promising candidate in catalysis, whereas their contribution to the adsorption of organic pollutants is rarely reported; especially adsorption mechanisms between cobalt and organics remain obscure. In this work, single-atom cobalt incorporated carbon nanofibers (CoSA-CNF) was synthesized via the electrostatic spinning technique. CoSA-CNF showed efficient adsorption for both sulfadiazine (SDZ) and roxarsone (ROX), with qe values of 413.16 and 338.42 mg/g fitted by the Langmuir-Freundlich isotherm at room temperature. Characterizations and density functional theory (DFT) calculations illustrated that CoSA-CNF carrying two configurations (Co-N3 and Co-N4) preferred to adsorb SDZ and ROX at Co-N3 sites with higher adsorption energy. The continuous-flow tests in a filtration cell with a CoSA-CNF membrane showed the membrane exhibited a superior recyclability and robust durability for SDZ and ROX removal during 54 h continuous operation without obvious decline. Moreover, the membrane was able to be rapidly regenerated by peroxymonosulfate (PMS) activation. In all, this study reports single-atom cobalt incorporated CNF as an efficient adsorbent for eliminating organic pollutants with the advantage of rapid regeneration, and demonstrates that the Co-N3 configuration is more favorable to adsorb organics than the Co-N4 configuration.