Degradation of norfloxacin by MOF-derived lamellar carbon nanocomposites based on microwave-driven Fenton reaction: Improved Fe(III)/Fe(II) cycle.

In this paper, a new type of iron-based magnetic nanoparticle material embedding mesoporous carbon (Fe@C) was prepared by simple pyrolysis of a MIL-101-Fe precursor and employed in the microwave-catalyzed degradation of norfloxacin (NOR) with the presence of HO. Characterization results showed successful anchoring of Fe nanoparticles in the carbon matrix. Under optimal treatment conditions (Calcination temperature = 700 °C, HO dosage = 40 mM, MW power = 500 W, NOR dosage = 50 mg L and initial pH = 4), the degradation efficiency of NOR reached 95.22%. The catalyst showed exceptional degradation properties over a relatively wide pH range. The mesoporous carbon in the catalyst promoted electron transfer, enhanced the Fe(III)/Fe(II) cycle, increased contact between Fe and Fe with HO, and accelerated the production of ·OH. Furthermore, density functional theory (DFT) calculations were used to predict the fragile active sites in NOR and to analyze the degradation pathway of NOR in combination with intermediates. Fe@C retained good activity after 5 cycles. Reduced toxicity of intermediates predicted by T.E.S.T. compared to NOR. This study presented a new avenue for the rational design of Fe-carbon composites as microwave-assisted Fenton-like catalysts for potential applications in wastewater treatment.