Engineering of a wafer-shaped titanium-based catalyst of TiO₂/MIL-125(Ti)@Ti₃C₂ or enhanced Fenton-like degradation of Congo red: optimization, mechanistic study, and reusability

A titanium-based Fenton-like heterogeneous catalyst was synthesized from titanium dioxide (TiO₂), MIL-125(Ti), and Ti₃C₂ MXene for degrading the notorious Congo red (CR). The successful combination of the titanium components was assured by bountiful characterization apparatuses. Optimization of the conditions for the Fenton-like degradation of CR dye was performed by studying the impact of the pH and temperature of the catalytic system, the dosage of TiO₂/MIL-125(Ti)@Ti₃C_2, the concentrations of hydrogen peroxide (H₂O₂) and CR, and the mass ratio between the catalyst’s components. A kinetic study was executed on the degradation of CR and H₂O₂ during a reaction time of 60 min using First-order and Second-order models. The degradation pathway of CR by TiO₂/MIL-125(Ti)@Ti₃C₂ was investigated by the scavenging test. Additionally, Adsorption and catalytic degradation mechanisms were explored using X-Ray Photoelectron Spectroscopy (XPS) analysis. The cycling test proceeded on TiO₂/MIL-125(Ti)@Ti₃C₂ for five succeeding Fenton-like degradation runs of CR dye. Ultimately, the Ti-based heterogeneous catalyst exhibited superior adsorption and Fenton-like degradation performance toward the anionic dye with a good recyclability feature.