Catalytic MOF-Based Hybrids for Wastewater Remediation: Advances, Challenges and Future Perspectives

The growing occurrence of persistent and emerging contaminants in wastewater has intensified the need for catalytic materials that combine high activity with aqueous stability, recoverability, and long-term reusability. Metal–organic framework (MOF)-based hybrids provide a versatile platform for wastewater remediation by integrating porous MOF structures with metal oxides, carbonaceous materials, polymers, magnetic nanoparticles, and bio-derived supports. This review critically evaluates the relationships among hybrid composition, pore accessibility, surface chemistry, active-site environment, charge transfer, reactive oxygen species generation, and treatment performance in adsorption-assisted remediation, photocatalysis, and advanced oxidation processes. Representative studies report adsorption capacities exceeding 250 mg g−1 for functionalized UiO-66 systems and degradation efficiencies of approximately 90–98% within 40–90 min for selected Fe-, Cu-, Co-, and semiconductor-coupled MOF systems. However, these values cannot be directly ranked because pollutant concentration, catalyst dosage, pH, oxidant loading, irradiation conditions, and contact time differ substantially among studies. Moreover, pollutant disappearance is frequently reported without corresponding mineralization or detoxification measurements, limiting the assessment of actual treatment effectiveness. The available evidence indicates that Fe-based MOFs provide strong redox activity for Fenton-like processes, whereas Zr-based frameworks generally offer greater hydrolytic stability; hybridization with carbonaceous or semiconductor components can further improve adsorption, charge separation, and catalyst recovery, although long-term leaching and stability remain insufficiently quantified. The most important research priorities are therefore real-wastewater validation, standardized performance reporting, quantitative metal-leaching assessment, repeated-cycle stability testing, differentiation between removal, degradation, mineralization, and detoxification, and pilot-scale techno-economic evaluation. By integrating material design, catalytic mechanisms, quantitative performance, and practical limitations, this review identifies the conditions required to advance MOF-based hybrids from laboratory demonstrations toward reliable wastewater-treatment technologies.