Challenges Facing Sustainable Visible Light Induced Degradation of Poly- and Perfluoroalkyls (PFA) in Water: A Critical Review

Poly- and perfluoroalkyls (PFAs) are now designated as serious threats to the environment. More than 4700 PFAs, along with their precursors, show a high degree of persistence and long-range spreading in soils and waters causing recalcitrant bioaccumulation in plants, fish, birds, and mammals causing health hazards all along the food chain. Visible-light induced degradation of PFA in pure water using photocatalysts, a potentially sustainable advanced oxidation process, showed exciting results in laboratories for both complete and partial mineralization of these toxins. However, none of the methods and materials have been considered so far for upscaling toward practical applications due to several hard-to-resolve challenges. This Review provides a critical analysis of the recent advancements in photocatalytic remediation of aqueous PFA under visible light irradiation and addresses possible future directions to valorize some of the prospective methods and materials to practical applications.