Superior visible light-mediated catalytic activity of a novel N-doped, Fe3O4-incorporating MgO nanosheet in presence of PMS: Imidacloprid degradation and implications on simultaneous bacterial inactivation
Somaye Akbari, Gholamreza Moussavi, Jérémie Decker, M. Luisa Marín, Francisco Boscá, Stefanos Giannakis
Abstract
Impressive Imidacloprid (IMD) degradation and bacterial inactivation were attained through the photocatalytic activation of peroxymonosulfate (PMS) via a novel, N-doped MgO@Fe3O4, under visible light. After complete characterization (XPS, XRD, FT-IR, FE-SEM, EDX, HRTEM, DRS, BET, VSM, and EIS), using [PMS]=75 mg/L, [N-MgO@Fe3O4]=150 mg/L at pH=5.6, around 95% of 10 mg/L IMD was degraded within 60 min; highly synergic interactions between the various catalytic routes were revealed. Extensive scavenger tests and EPR studies revealed that SO4•-, HO•, and 1O2 are generated and play a key role in IMD degradation. Tap water experiments proceeded unhindered, and only the presence of high HCO3- and PO43- concentration resulted in a decrease in the IMD degradation efficiency, while negligible leaching, magnetization, notable separation, and reusability properties were well-preserved for six repetitive cycles. Finally, E. coli disinfection was achieved before IMD degradation, possibly affected by its transformation byproducts. The overall efficacy of N-MgO@Fe3O4 indicated the potential for implementation in contaminated waters.