Recent advances in MOF synthesis and their applications in mixed-matrix membranes for water treatment: A critical review

Global water scarcity demands innovative treatment technologies, yet conventional membranes face persistent challenges including fouling, the permeability-selectivity trade-off, and limited contaminant removal efficiency. Although mixed matrix membranes (MMMs) offer promising results, critical gaps remain in understanding how metal-organic framework (MOF) integration can simultaneously overcome these fundamental limitations. This review uniquely synthesizes recent breakthrough developments in MOF-based MMMs, focusing on innovative solutions that address multiple performance challenges. The objectives of this review are to evaluate sustainable MOF synthesis methods reducing environmental impact, analyze advanced fabrication techniques achieving superior filler-matrix integration, and assess performance breakthroughs in removing diverse contaminants. The key innovations highlighted include photocatalytic self-cleaning membranes, dual cross-linking strategies overcoming permeability-selectivity trade-offs, multi-functional systems with simultaneous contaminant removal capabilities, and bio-MOF integration. These advances have significantly enhanced membrane stability, reusability, antifouling capability, and filler-matrix compatibility, achieving remarkable removal efficiencies for heavy metal ions (>99%), dyes (>95%), salts (>99%), and emerging contaminants. Despite these achievements, critical challenges persist, including aqueous stability limitations, filler aggregation, performance degradation over operational cycles, and scalability barriers. To address these limitations, the review proposes scalable green synthesis methods, predictive modeling for lifespan optimization, and comprehensive stability assessments under realistic industrial conditions. This analysis provides a roadmap for advancing MOF-based MMMs to commercially viable water treatment solutions. • Green MOF synthesis methods improve scalability and sustainability for water treatment applications. • Novel strategies like NIPS-SC, dual cross-linking, and in-situ polymerization minimize interfacial defects and enhance membrane performance. • MOF-based membranes yield high removal rates for metals, dyes, salts, and emerging contaminants. • Aqueous stability, performance degradation, filler aggregation, and scalability challenges hinder transition from laboratory to industrial applications. • Commercial viability requires scalable green synthesis, predictive modeling, industrial testing, and systematic regeneration efficiency evaluations.