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Jmol reactive7/1/2023 In addition to separation methods, there is an urgent need for more effective methods of PFAS destruction. Separation-based technologies are the most common treatment method for PFAS-contaminated water, but this approach still requires destruction of the secondary PFAS waste stream, leading to other logistical, environmental, and health concerns 4. Meanwhile, PFAS have dispersed globally in groundwater for over sixty years, reaching far from pollution sources 3, and their thermal and chemical stability pose significant technical challenges for remediation. Long-term studies reveal that PFAS can bioaccumulate differently than other contaminants owing to their high water solubility, thus entering the body through potable water and causing diverse chronic health effects 2. Per- and poly- fluoroalkyl substances (PFAS) are man-made chemicals that have a high stability in the environment due to the strength of the carbon–fluorine (C-F) bond 1. We conclude that Nb-doped TiO 2 is a promising alternative EAOP catalytic material with increased activity towards generating reactive oxygen species and warrants further development for electrochemically destroying PFAS contaminants. The capability of Nb-doped TiO 2 to destroy two common species of PFAS in challenge water was tested, and moderate reduction by ~ 30% was observed, comparable to that of Ti 4O 7 using a simple three-electrode configuration. TiO 2 samples were synthesized with Nb doping concentration at 10 at.%, heat treated at temperatures from 800 to 1100 ☌, and found to exhibit high oxidative stability and high generation of reactive oxygen free radical species. The results indicate a non-monotonic trend in which Nb doping below 6.25 at.% is expected to reduce performance relative to TiO 2, while higher concentrations up to 12.5 at.% lead to increased performance, approaching that of state-of-the-art Magnéli Ti 4O 7. Calculations based on density functional theory are used to predict the overpotential for oxygen evolution at these candidate electrodes, which must be high in order to oxidize PFAS. ![]() Herein, we report on the performance of niobium (Nb) doped rutile titanium oxide (TiO 2) as a novel EAOP catalytic material, combining theoretical modeling with experimental synthesis and characterization. Generating these reactive species electrochemically at electrodes provides an advantage over other oxidation processes that rely on chemicals or other harsh conditions. Central to EAOP are catalysis-induced reactive free radicals for breaking the carbon fluorine bonds in PFAS. Electrochemical advanced oxidative processes (EAOP) are a promising route to destroy recalcitrant organic contaminants such as per- and polyfluoroalkyl substances (PFAS) in drinking water.
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