Exploring Solar Energy Solutions for Per‐ and Polyfluoroalkyl Substances Degradation: Advancements and Future Directions in Photocatalytic Processes

Abstract

Concerns about per‐ and polyfluoroalkyl substances (PFAS) pollution are escalating globally due to the discovery of their widespread environmental distribution, accompanied by their migration, bioaccumulation, and toxic potential for plants, animals, and humans. Several technologies have been developed for their remediation since standard water treatment methods often fail. However, these approaches require large energy consumption and, at times, exacerbate environmental issues. In this context, photocatalytic degradation holds promise as a reliable technological solution for PFAS mineralization. However, to date, it primarily relies on the degradation of perfluorooctanoic acid using high‐energy gap semiconductor oxides that necessitate high‐power artificial ultraviolet sources for excitation and, at times, the use of strong chemical oxidants. This review examines chemical‐free catalysts and mechanisms recently documented in the literature to outline a roadmap for the realization of solar‐driven mineralization of all PFAS compounds. To this end, conventional wide‐bandgap semiconductor oxides are delved into and strategies to extend their spectral absorbance while enhancing charge separation with a focus on the proposed degradation pathways are explored, that are fundamental to designing technologically relevant photodegradation systems.