Emerging trends in photocatalyst-based metal-organic frameworks for PFAS degradation

Per - and polyfluoroalkyl substances (PFAS) are highly persistent pollutants in the environment that pose significant health hazards due to their strong chemical resilience and widespread industrial use. Traditional treatment techniques, such as adsorption and reverse osmosis, often struggle with drawbacks like high energy requirements and limited effectiveness against both short- and long-chain PFAS compounds. Among the innovative degradation methods, photocatalysis has gained attention as a viable solution, especially when coupled with metal-organic frameworks (MOFs). MOFs are particularly suited for this purpose due to their high surface area, customizable structures, and superior light absorption properties. This review highlights the latest developments in MOF-based photocatalytic systems for PFAS elimination, focusing on structural modifications, the use of dual metals, and surface area enhancement. It examines specific approaches like functionalizing ligands, doping metals, and incorporating sacrificial agents to improve charge separation, adsorption efficiency, and the generation of reactive species. Additionally, the integration of MOFs with semiconductor materials and their roles in advanced processes such as photo-Fenton and photo-electro-Fenton systems are also discussed. The review also addresses ongoing challenges, including incomplete defluorination and the need to better understand degradation pathways. In conclusion, it presents future directions aimed at improving the performance, scalability, and environmental sustainability of MOF-assisted photocatalytic PFAS treatment. • Comprehensive evaluation of MOFs for PFAS degradation. • Detailed comparison of MOF synthesis methods. • Mechanistic insights into photocatalytic and photo-Fenton degradation. • Strategies to improve photocatalytic performance for PFAS degradation. • Research gaps and future directions in MOF-based photocatalysts for PFAS.