Breaking the ‘forever’ bond: photocatalytic degradation of per- and polyfluoroalkyl substances using ternary photocatalysts

Abstract

Per- and polyfluoroalkyl substances (PFAS) are persistent eco-pollutants that pose significant risks to human health and ecosystems. The US EPA and EU databases catalog over 14,900 PFAS, labeling stable C-F bonds as ‘forever’ chemicals. This review critically examines advancements in photocatalytic degradation strategies for PFAS using multi-modal ternary functional materials. An overview of the occurrence, toxicity, and ecological impact highlights the concurrent need for effective remediation techniques. The article focuses on the design, synthesis, and performance of ternary photocatalysts, emphasizing their enhanced charge separation, broad spectral absorption, tailored band gap, and synergistic effects. Key aspects of material engineering strategies, degradation mechanisms, efficiency amplification strategies, and scalability prospects have been highlighted. The discussion elucidates emerging Z-scheme, S-scheme, and C-scheme heterojunctions for tailored and efficient photodegradation strategies, addressing the limitations of PFAS photodegradation. Prospects include developing highly paramagnetic, non-corrosive catalysts and integrating advanced analytical techniques for mechanistic insights. Analyzing the obstacles to incorporating these strategies into real-time, efficient, sustainable, and scalable degradation units paves the way for a brighter future in PFAS remediation.