Highly efficient and continuous activation of O2 by a novel FexP-FeCu composite for water purification and insights into the activation mechanisms through DFT calculation

Hongyun Niu; Hongzhou Lv; Li Mao; Yaqi Cai; Xiaoli Zhao; Fengchang Wu

doi:10.1016/j.jhazmat.2023.132267

Highly efficient and continuous activation of O₂ by a novel Fe_xP-FeCu composite for water purification and insights into the activation mechanisms through DFT calculation

J Hazard Mater. 2023 Oct 5:459:132267. doi: 10.1016/j.jhazmat.2023.132267. Epub 2023 Aug 11.

Authors

Hongyun Niu¹, Hongzhou Lv², Li Mao¹, Yaqi Cai³, Xiaoli Zhao⁴, Fengchang Wu⁴

Affiliations

¹ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
² Institute of Resources and Environment Engineering, Shanxi University, Taiyuan, Shanxi Province 030006, China.
³ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Environment and Health, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, Zhejiang Province 310013, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: caiyaqi@rcees.ac.cn.
⁴ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.

PMID: 37586243
DOI: 10.1016/j.jhazmat.2023.132267

Abstract

Degradation of organic pollutants through O₂ activation catalyzed by transitional metals is challenging without addition of external chemicals and input of energy. We prepare a novel Fe based catalyst by compositing carbon, iron phosphide (Fe_xP), iron carbide (Fe_xC), Fe⁰ and Cu NPs, which can continuously activate O₂ to produce high amount of ¹O₂,·O₂^- and·OH radicals in a wide pH range. DFT calculation discloses that O₂ molecules are dissociated into *O or exist as O-O in various configurations. The Fe-O₂, Cu-O₂ and FeP-O₂ surfaces can react with H₂O molecules to generate *OOH, *OH and/or OH^-. The sorbed-O₂ intermediates on Fe_xC surface might be released as ¹O₂ or·O₂^-. The oxidative O₂-sorbed surfaces and in-situ produced oxygen reactive species contribute to the efficient and pH-indenpendent degradation of organic pollutants. Cu NPs accelerate Fe²⁺/Fe³⁺ cycles and offer impetus to initiate O₂ activation due to the potential difference between Fe and Cu. The recycling test and XPS results confirm that the mutual electron transferring among carbon, Fe_xC, Fe_xP, Fe and Cu maintains reactivity and stability of the catalysts.

Keywords: Active sorbed-O(2) species; Bimetal FeCu; DFT calculation; Degradation of organic pollutants; O(2) activation.