1 Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada.
2 Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 34132, Republic of Korea.
3 Lyten Inc., San Jose, CA 95134, USA.
4 Department of Environment & Energy Engineering, Changwon National University, 20 Changwondaehak-ro, Changwon, Gyeongnam 51140, Republic of Korea. Electronic address: dwjeong@changwon.ac.kr.
5 Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada. Electronic address: Jaehoon.hwang@concordia.ca.

Per- and polyfluoroalkyl substances (PFAS), such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are persistent environmental pollutants posing significant risks to ecosystems, drinking water safety, and human health. Conventional PFAS removal methods effectively mitigate contamination but face challenges such as high operational costs, energy demands, and secondary waste production. Photocatalytic methods have emerged as a promising alternative, utilizing light-activated semiconductors to generate reactive oxygen species (ROS), which facilitate the efficient degradation of PFAS into non-toxic byproducts. Advanced photocatalysts, such as titanium dioxide (TiO₂), demonstrate significant potential under UV and visible light, though challenges remain, including low activity under visible light, rapid recombination of photogenerated electron-hole pairs, and inefficient carrier utilization. To address these limitations, strategies such as non-metal and metal doping and combining wide- and narrow-bandgap semiconductors have been explored to enhance light absorption, photocatalytic efficiency, and stability. Recent developments in photocatalysts, including PMR technology (80 % PFOA removal in 2 h) (Junker et al., 2024b), Bi₄O₇-modified Ga₂O₃ (59.6 % defluorination) (Chen et al., 2024), and lead-doped TiO₂/rGO (98 % PFOA removal in 24 h) (Chowdhury and Choi, 2023), have improved PFAS degradation by optimizing light absorption, charge separation, and surface adsorption. Hybrid systems integrating photocatalysis with other treatment methods, such as adsorption and electrochemical oxidation, offer a path toward sustainable, efficient PFAS remediation. This review explores the latest advancements in photocatalytic technologies and highlights future directions, including the development of cost-effective, environmentally friendly materials and field-scale validation. These efforts emphasize the potential of photocatalysis as a cornerstone in achieving sustainable water treatment solutions and protecting environmental and public health.