MXene-Derived Nano\nN‑TiO<sub>2</sub>@MXene\nLoaded with Fe<sub>3</sub>O<sub>4</sub> for Photo-Fenton Synergistic\nDegradation of Phenol

Phenol\nis a volatile organic compound, and conventional\ntreatment\nprocesses prove to be ineffective for its degradation. The designable\nelectron transfer structures of Fenton-based catalysts show great\npotential for wastewater treatment. However, attaining a balance between\nrecycling and degradation efficiency remains a challenge. Herein,\nwe prepared a photocatalyst with improved visible-light excitation\ncharacteristics. Magnetic N-TiO<sub>2</sub>/Fe<sub>3</sub>O<sub>4</sub>@MXene was prepared by loading N-TiO<sub>2</sub> nanoparticles and\nFe<sub>3</sub>O<sub>4</sub> onto multilayered MXenes. N-TiO<sub>2</sub>/Fe<sub>3</sub>O<sub>4</sub>@MXene exhibited stable magnetic characteristics\n(27.1 emu/g) and a high degradation capacity for phenol. The catalyst\nalso showed better performance for phenol removal under simulated\nsolar-light (200–800 nm) irradiation compared with those of\nother catalysts. The phenol removal rate of the catalyst in the concentration\nrange of 20–60 ppm reached 98% after 30 min of solar-light\nirradiation. The degradation curves of phenol were kinetically fitted.\nAfter four cycles of testing, the material maintained a high efficiency\nfor the degradation of phenol. A total organic carbon removal rate\nof 61% was achieved in 10 min. The intermediates of phenol degradation\nwere determined via liquid chromatography–mass spectrometry\nto gain insights into the degradation pathways of phenol. This study\npaves the way for the development of efficient photo-Fenton-based\ncatalytic systems with good magnetic separation capabilities, which\ncan promote their application in wastewater treatment.