Ti3C2 MXene promoted Fe3+/H2O2 fenton oxidation: Comparison of mechanisms under dark and visible light conditions

The performance and mechanisms of a titanium carbide (Ti 3 C 2 ) MXene modified Fe 3+ /hydrogen peroxide (H 2 O 2 ) system were compared in detail under dark and visible light conditions, with a new mechanism proposed for the reaction and reduction of MXene by Fe 3+ . Using Bisphenol A (BPA) as the target pollutant, the degradation of BPA by the Fe 3+ /H 2 O 2 system was improved after adding MXene in the dark, and the degradation rate of BPA was ≥ 95 % within 12.5 min under visible light, six times higher than that in the dark. Fe 2+ was ascertained to be the effective component responsible for H 2 O 2 activation to produce ·OH. SEM , XPS, ICP, XRD, and FTIR spectroscopy , analyses show that MXene and Fe 3+ form a complex, and then MXene reacts with Fe 3+ by breaking the Ti–C bonding to accelerate the Fe 3+ /Fe 2+ cycle. MXene uses photogenerated electrons to promote this reaction under visible light. In addition, quenching experiments and electron spin resonance spectroscopy results show that ·OH and O 2 •− are the main reactive oxygen species under visible light, while ·OH is the main active species in the dark. MXene thus effectively uses O 2 to form O 2 •− under visible light and promotes the Fe 3+ /Fe 2+ cycle. This study provides a theoretical basis for the combination of visible light catalysis and the advanced oxidation process of a Ti 3 C 2 MXene.