MXene-Derived Nano N‑TiO2@MXene Loaded with Fe3O4 for Photo-Fenton Synergistic Degradation of Phenol

Phenol is a volatile organic compound, and conventional treatment processes prove to be ineffective for its degradation. The designable electron transfer structures of Fenton-based catalysts show great potential for wastewater treatment. However, attaining a balance between recycling and degradation efficiency remains a challenge. Herein, we prepared a photocatalyst with improved visible-light excitation characteristics. Magnetic N-TiO2/Fe3O4@MXene was prepared by loading N-TiO2 nanoparticles and Fe3O4 onto multilayered MXenes. N-TiO2/Fe3O4@MXene exhibited stable magnetic characteristics (27.1 emu/g) and a high degradation capacity for phenol. The catalyst also showed better performance for phenol removal under simulated solar-light (200–800 nm) irradiation compared with those of other catalysts. The phenol removal rate of the catalyst in the concentration range of 20–60 ppm reached 98% after 30 min of solar-light irradiation. The degradation curves of phenol were kinetically fitted. After four cycles of testing, the material maintained a high efficiency for the degradation of phenol. A total organic carbon removal rate of 61% was achieved in 10 min. The intermediates of phenol degradation were determined via liquid chromatography–mass spectrometry to gain insights into the degradation pathways of phenol. This study paves the way for the development of efficient photo-Fenton-based catalytic systems with good magnetic separation capabilities, which can promote their application in wastewater treatment.