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Activation of Peroxymonosulfate by Oxygen Vacancies-enriched Cobalt-doped Black TiO_2 Nanotubes for Removal of Organic Pollutants

Lim, Jonghun and Yang, Yang and Hoffmann, Michael R. (2019) Activation of Peroxymonosulfate by Oxygen Vacancies-enriched Cobalt-doped Black TiO_2 Nanotubes for Removal of Organic Pollutants. Environmental Science and Technology, 53 (12). pp. 6972-6980. ISSN 0013-936X. PMCID PMC6587153. doi:10.1021/acs.est.9b01449.

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Cobalt-mediated activation of peroxymonosulfate (PMS) has been widely investigated for the oxidation of organic pollutants. Herein, we employ cobalt-doped Black TiO_2 nanotubes (Co-Black TNT) for the efficient, stable, and reusable activator of PMS for the degradation of organic pollutants. Co-Black TNTs induce the activation of PMS by itself and stabilized oxygen vacancies that enhance the bonding with PMS and provide catalytic active sites for PMS activation. A relatively high electronic conductivity associated with the coexistence of Ti^(4+) and Ti^(3+) in Co-Black TNT enables an efficient electron transfer between PMS and the catalyst. As a result, Co-Black TNT is an effective catalyst for PMS activation, leading to the degradation of selected organic pollutants when compared to other TNTs (TNT, Co-TNT, and Black TNT) and other Co-based materials (Co_3O_4, Co-TiO_2, CoFe_2O_4, and Co_3O_4/rGO). The observed organic compound degradation kinetics are retarded in the presence of methanol and natural organic matter as sulfate radical scavengers. These results demonstrate that sulfate radical is the primary oxidant generated via PMS activation on Co-Black TNT. The strong interaction between Co and TiO_2 through Co–O–Ti bonds and rapid redox cycle of Co^(2+)/Co^(3+) in Co-Black TNT prevents cobalt leaching and enhances catalyst stability over a wide pH range and repetitive uses of the catalyst. Electrode-supported Co-Black TNT facilitates the recovery of the catalyst from the treated water.

Item Type:Article
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URLURL TypeDescription CentralArticle
Lim, Jonghun0000-0002-2943-1846
Yang, Yang0000-0003-3767-8029
Hoffmann, Michael R.0000-0001-6495-1946
Alternate Title:Activation of Peroxymonosulfate by Oxygen Vacancies-enriched Cobalt-doped Black TiO2 Nanotubes for Removal of Organic Pollutants
Additional Information:© 2019 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. Received: March 7, 2019; Revised: May 10, 2019; Accepted: May 15, 2019; Published: May 15, 2019. This research was supported by the Bill and Melinda Gates Foundation (BMGF RTTC Grant Nos. OPP1111246 and OPP1149755). The authors declare no competing financial interest.
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1111246
Bill and Melinda Gates FoundationOPP1149755
Issue or Number:12
PubMed Central ID:PMC6587153
Record Number:CaltechAUTHORS:20190516-074004029
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Official Citation:Activation of Peroxymonosulfate by Oxygen Vacancies-Enriched Cobalt-Doped Black TiO2 Nanotubes for the Removal of Organic Pollutants. Jonghun Lim, Yang Yang, and Michael R. Hoffmann. Environmental Science & Technology 2019 53 (12), 6972-6980 DOI: 10.1021/acs.est.9b01449
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:95526
Deposited By: Tony Diaz
Deposited On:16 May 2019 15:11
Last Modified:16 Nov 2021 17:13

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