Tuning the intrinsic catalytic sites of magnetite to concurrently enhance the reduction of H2O2 and O2: Mechanism analysis and application potential evaluation

Ling Li; Min Cheng; Eydhah Almatrafi; Lei Qin; Shiyu Liu; Huan Yi; Lu Yang; Zhexin Chen; Dengsheng Ma; Mingming Zhang; Xuerong Zhou; Fuhang Xu; Chengyun Zhou; Lin Tang; Guangming Zeng; Cui Lai

doi:10.1016/j.jhazmat.2023.131800

Tuning the intrinsic catalytic sites of magnetite to concurrently enhance the reduction of H₂O₂ and O₂: Mechanism analysis and application potential evaluation

J Hazard Mater. 2023 Sep 5:457:131800. doi: 10.1016/j.jhazmat.2023.131800. Epub 2023 Jun 7.

Authors

Ling Li¹, Min Cheng¹, Eydhah Almatrafi², Lei Qin¹, Shiyu Liu¹, Huan Yi¹, Lu Yang¹, Zhexin Chen¹, Dengsheng Ma¹, Mingming Zhang¹, Xuerong Zhou¹, Fuhang Xu¹, Chengyun Zhou³, Lin Tang¹, Guangming Zeng⁴, Cui Lai⁵

Affiliations

¹ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
² Center of Research Excellence in Renewable Energy and Power Systems, Center of Excellence in Desalination Technology, Department of Mechanical Engineering, Faculty of Engineering-Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
³ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China; Center of Research Excellence in Renewable Energy and Power Systems, Center of Excellence in Desalination Technology, Department of Mechanical Engineering, Faculty of Engineering-Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
⁴ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China; Center of Research Excellence in Renewable Energy and Power Systems, Center of Excellence in Desalination Technology, Department of Mechanical Engineering, Faculty of Engineering-Rabigh, King Abdulaziz University, Jeddah 21589, Saudi Arabia. Electronic address: zgming@hnu.edu.cn.
⁵ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China. Electronic address: laicui@hnu.edu.cn.

PMID: 37302189
DOI: 10.1016/j.jhazmat.2023.131800

Abstract

Heterogeneous Fenton-like process based on H₂O₂ activation has been widely tested for water purification, but its application still faces some challenges such as the use of high doses of chemicals (including catalysts and H₂O₂). Herein, a facile co-precipitation method was utilized for small-scale production (∼50 g) of oxygen vacancies (OVs)-containing Fe₃O₄ (V_o-Fe₃O₄) for H₂O₂ activation. Experimental and theoretical results collaboratively verified that H₂O₂ adsorbed on the Fe site of Fe₃O₄ tended to lose electrons and generate O₂^•-. While the localized electron from OVs of V_o-Fe₃O₄ could assist in donating electrons to H₂O₂ adsorbed on OVs sites, this allowed more H₂O₂ to be activated to ^•OH, which was 3.5 folds higher than Fe₃O₄/H₂O₂ system. Moreover, the OVs sites promoted dissolved oxygen activation and decreased the quenching of O₂^•- by Fe(III), thus promoting the generation of ¹O₂. Consequently, the fabricated V_o-Fe₃O₄ achieved much higher oxytetracycline (OTC) degradation rate (91.6%) than Fe₃O₄ (35.4%) at a low catalyst (50 mg/L) and H₂O₂ dosage (2 mmol/L). Importantly, further integration of V_o-Fe₃O₄ into fixed-bed Fenton-like reactor could effectively eliminate OTC (>80%) and chemical oxygen demand (COD) (21.3%∼50%) within the running period. This study provides promising strategies for enhancing the H₂O₂ utilization of Fe mineral.

Keywords: Electron transfer; Fe(3)O(4); H(2)O(2) activation; Oxygen vacancies; Water treatment.