Metal-organic frameworks for catalytic degradation of emerging dye contaminants in wastewater: A critical review of material design, reaction mechanisms, and engineering application

Industrial effluents from the textile, dyeing, and papermaking industries commonly contain dyes that are compositionally complex, environmentally persistent, and often resistant to biodegradation, posing potential ecological and human–health risks. These attributes render the treatment of dye–laden wastewater a major challenge in global water–pollution control. Conventional physical, chemical, and biological methods (e.g., adsorption, coagulation/precipitation, and redox processes) are constrained by limited efficiency, unfavorable costs, and risks of secondary pollution. Metal–organic frameworks (MOFs), with ordered porosity, tunable metal nodes, tailorable linkers, and adjustable pore microenvironments, offer a versatile platform for dye adsorption, catalytic degradation, photocatalysis, electrocatalysis, and membrane–assisted separation. This review critically summarizes recent advances in MOF–based dye degradation from the perspectives of material design, reaction mechanisms, and engineering applicability. Particular attention is given to how metal–node regulation, linker functionalization, defect engineering, morphology control, activation strategies, and multicomponent construction affect active–site accessibility, interfacial enrichment, charge transfer, reactive species generation, and dye–specific degradation pathways. Finally, key challenges related to structural stability, metal leaching, recyclability, catalyst recovery, mineralization, toxicity evolution, real–wastewater adaptability, and continuous–flow implementation are discussed. This review provides a structure–mechanism–application framework for designing practical MOF–based catalytic systems for dye wastewater remediation.