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

Abstract

• Synergistic effect between adsorption and Fenton-like for removing CR. • The formed intermediated during the CR degradation were demonstrated by GC–MS. • The CR adsorption (%) was 43.67 % and the degradation (%) reached 99.05 % at pH=3. • The •OH radicals in the main ROS, as elucidated from the quenching test. A titanium-based Fenton-like heterogeneous catalyst was synthesized from titanium dioxide (TiO 2 ), MIL-125(Ti), and Ti 3 C 2 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 TiO 2 /MIL-125(Ti)@Ti 3 C 2 , the concentrations of hydrogen peroxide (H 2 O 2 ) and CR, and the mass ratio between the catalyst’s components. A kinetic study was executed on the degradation of CR and H 2 O 2 during a reaction time of 60 min using First-order and Second-order models. The degradation pathway of CR by TiO 2 /MIL-125(Ti)@Ti 3 C 2 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 TiO 2 /MIL-125(Ti)@Ti 3 C 2 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.