Heterogeneous photocatalytic decomposition of per- and poly-fluoroalkyl substances: A review

Per- and poly-fluoroalkyl substances (PFASs) as emergent contaminants are generating serious environmental and health issues. An imminent task is thus to develop effective technologies to completely remove and ideally decompose PFASs through physical and/or chemical routes. Heterogeneous photocatalysis, which directly utilizes sunlight to drive the chemical decomposition of many organic compounds, is a promising solution to remediating PFASs-contaminated environment. In this review, the current progress of heterogeneous photocatalytic technology for decomposing PFASs is systematically summarized. The significance of environmental factors during heterogeneous photocatalysis is discussed from three aspects including anaerobic vs aerobic, acidic vs alkaline, and light use vs light loss. The associated reaction mechanisms and reaction routes are analyzed based on the stepwise change of PFASs molecular structures. Some further issues regarding PFASs heterogeneous photocatalysis are briefly pointed out along with the potential industrial applications of this technology.