Advanced Photocatalysts for PFAS Removal: From Fundamental Mechanisms to Sustainable Water Treatment Solutions

ABSTRACT Per‐ and polyfluoroalkyl substances (PFAS) are recognized as a global environmental concern because of their toxicity, persistence, and strong resistance to conventional treatment processes. Due to their stable carbon‐fluorine bond, PFAS remain in the environment for long periods and can accumulate in living organisms. Photocatalysis has been employed as an effective strategy to degrade PFAS into smaller compounds and inorganic products under UV, visible, or solar light. In this review, a critical assessment of PFAS degradation using advanced oxidation processes is presented as a treatment option for reducing their levels in water systems. The physicochemical properties, sources, environmental transport pathways, and toxicological effects of PFAS are first outlined to provide a comprehensive background. Subsequently, the key mechanisms and steps involved in photocatalytic degradation are described in detail. The degradation performance across various catalyst systems and operating conditions is systematically compared. Finally, the current technological bottlenecks are critically examined, including insufficient visible‐light responsiveness, limited catalyst stability and reusability, incomplete PFAS defluorination, and significant challenges in process scale‐up. Future research directions are outlined to optimize catalyst design, develop efficient hybrid systems, and facilitate the translation of these technologies toward full‐scale water treatment applications.