Magnetic field-enhanced radical intensity for accelerating norfloxacin degradation under FeCu/rGO photo-Fenton catalysis

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2021-09, Vol.420, p.127634, Article 127634
• Main Authors: Dan, Hongbing, Kong, Yan, Yue, Qinyan, Liu, Jiashuo, Xu, Xing, Kong, Wenjia, Gao, Yue, Gao, Baoyu
• Format: Article
• Language: English
• Subjects: FeCu/rGO; Heterogeneous Fenton catalysis; Magnetic field; Norfloxacin degradation; Radical intensity
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.127634

[Display omitted] •FeCu/rGO was facilely prepared via a one-step hydrothermal co-reduction process.•A strong synergistic effect between Fe and Cu species promoted NOR degradation.•Enhanced •OH and •O2–/•HO2 were observed with an external magnetic field (200 mT).•The magnetic field further accelerated NOR removal (34.1%) and H2O2 usage (27.0%).•The mechanism of magnetic field-improved FeCu/rGO photo-Fenton catalysis was proposed. Improving the efficiency of photo-induced carriers (e-/h+) is one of the most effective routes to accelerate the heterogeneous photo-Fenton process. Herein, inspired by inverse Lorentz forces of opposite charges in a magnetic field, an external magnetic field intensified photo-Fenton catalysis for norfloxacin (NOR) degradation was constructed under visible light irradiation. The reduced graphene oxide-supported Fe-Cu bimetal (FeCu/rGO), obtained by employing common iron powder as a reducing agent, was served as a model catalyst. Impressively, the intensities of both carriers and radicals (•OH and •O2–/•HO2) were increased after the normal photo-Fenton reactor was placed into two fixed permanent magnets (200 mT), leading to a 34.1% improvement in NOR removal. Meanwhile, the consumption of H2O2 was also critically boosted (from 65.1% to 92.1%). Combined with theoretical studies, the enhanced radicals were not only resulted from accelerated carrier separation but also extended O-O and O–H bonds in H2O2 and facilitated spin evolutions of 1[HO•↑···↓•OH] → 3[HO•↑···↑•OH] and 1[HOO•↑···↓•H] → 3[HOO•↑···↑•H]. This study offers an insight into the specific role of an external magnetic field in promoting heterogeneous photo-Fenton catalysis.