Enhanced photocatalytic degradation of organic contaminants over CaFe2O4 under visible LED light irradiation mediated by peroxymonosulfate. (30th January 2021)

• Record Type: Journal Article
• Authors: Guo, Sheng; Yang, Zhixiong; Zhang, Huali; Yang, Wei; Li, Jun; Zhou, Kun
• Is Part Of: Journal of materials science & technology. Volume 62(2021)
• Page Start: 34
• Page End: 43
• Publication Date: 2021-01-30
• Subjects: CaFe2O4 -- Peroxymonosulfate -- LED light -- Degradation -- DFT calculations; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2020.05.057
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: A simple sol-gel approach is proposed herein to fabricate CaFe2 O4 for the degradation of various organic pollutants (rhodamine B (RhB), tetracycline hydrochloride, humic acid, and methylene orange) under LED light irradiation mediated by peroxymonosulfate (PMS). The results indicate that the calcination temperature can significantly influence the performance of CaFe2 O4 for PMS activation, and the CaFe2 O4 sample obtained at 800 °C (CaFe2 O4 -800) exhibits the best efficiency in degrading RhB, which is much higher than that of Fe2 O3 -800. This can be attributed to the efficient separation of photogenerated electrons (e − ) and holes (h + ) by PMS, which is validated by transient photocurrent response and photoluminescence measurements. Results from density functional theory calculations indicate that the valence band of CaFe2 O4 -800 exhibits a high concentration of carriers and weak localization of electrons, which are favorable for PMS activation. Radical scavenging results confirm that h + and O2 − are the dominant reactive species. Moreover, CaFe2 O4 -800 not only demonstrated a stable performance during eight cycling runs with negligible iron leaching but also exhibited excellent degradation efficiency under natural water and sunlight. Finally, the mechanism and pathway of RhB degradation by the CaFe2 O4 -800/PMS/LED system are also proposed. This work presents the enormous prospect of CaFe2 O4 as an environmentally benign photocatalyst for PMS activation.