Thermal shock treatment of recyclable bimetallic MOF derived carbon composite for organics oxidation by advanced Fenton-Like technique

This study offers a bimetallic MIL-88 B Metal-Organic Frameworks (MOF) derived carbon composite Co/Ferrite MOF namely Co/Fe@C that is synthesized through a solvothermal route followed by a simple thermal shock treatment and used as a Fenton-like source. The synthesized Co/Fe@C morphology and elemental analysis are characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and vibrating sample magnetometer (VSM). Carbon based MOF demonstrated fascinating features as a Fenton source conducted in dark oxidation route. The material exposed a superior efficiency in treating various organic pollutants including basic (Malachite Green, MG) and acidic (Oil Orange SS, OOSS) dyes as a textile simulated effluent and tetracycline (TC) as a model pharmaceutical wastewater. The experimental results exhibited the optimum reaction conditions of 400 mg/L for H₂O₂ for all contaminants oxidation and ranged from 10 to 40 mg/L for Co/Fe@C catalyst at varied optimal pH values. Under optimal conditions, the Co/Fe@C catalyst achieved removal efficiencies reached to 100% for MG, 83% for OOSS, and 72% for TC within 30 min. Furthermore, for potential full-scale application, the kinetic investigation is highlighted and the reaction is following the second kinetic order. Also, to assure catalyst sustainability, the Co/Fe@C substance is reused after recovery for seven oxidation cycles with a reasonable decline in its activity that reached to 57, 45 and 42% removals for MG, OOSS and TC, respectively. Furthermore, the mechanism exploration indicated the active species involved oxidation process primarily affecting TC and OOSS oxidation is holes (h⁺) and MG is OH radicals.