Photocatalytic defluorination of perfluorooctanoic acid by surface defective BiOCl: Fast microwave solvothermal synthesis and photocatalytic mechanisms

Impacts of Reactor Configuration, Degradation Mechanisms, and Water Matrices on Perfluorocarboxylic Acid Treatment Efficiency by the UV/Bi3O(OH)(PO4)2 Photocatalytic Process

“…Degradation of all PFAS proceeded at similar rates in this reactor, as did the PFOA control experiment using no BOHP, which together indicates that photolysis was responsible and not photocatalysis. Unlike the lamps used in the immersion reactor experiments discussed above, those in the commercial reactor included 185 nm VUV emissions capable of directly photolyzing most PFAS. , Overall, F – recovery was significantly lower than that observed previously in the immersion reactor for PFOA, with PFHpA showing the lowest (23 ± 4%) and PFOA the highest (36 ± 2%), though no clear trend was observed. Since significant turbulence occurred where the recycled effluent and slurry reenter the influent reservoir (Figure C), air stripping is suspected to have resulted in loss of HF and other intermediate fluorinated compounds from the system.…”

“…Quenching of • OH by IPA markedly slowed PFOA degradation, with methanol and t -butanol having a similar effect (data not shown). While direct reaction of PFOA with • OH is known to be inefficient in homogeneous advanced oxidation, several works involving the reaction of PFOA at liquid–solid interfaces have reported similar results, including in photocatalytic and electrochemical systems. ,− Relating to the same behavior observed during PFOA degradation by a In 2 O 3 photocatalyst, Wu et al. proposed that • OH reacts with perfluoroalkyl radical intermediates formed by reaction of PFOA with h vb + (Reaction ) and thus accelerates the stepwise chain-shortening mineralization process .…”

Fe3+ Promoted the Photocatalytic Defluorination of Perfluorooctanoic Acid (PFOA) over In2O3

“…The decomposition of PFOA was initiated by direct hole oxidation, and the tight coordination of PFOA is essential for direct hole oxidation . Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is a useful technique for gaining insight into the mode of coordination between PFOA and semiconductor photocatalysts. , In situ DRIFTS was widely used to track the reaction intermediates and products to better understand reaction mechanisms. , …”

“…15 Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is a useful technique for gaining insight into the mode of coordination between PFOA and semiconductor photocatalysts. 16,17 In situ DRIFTS was widely used to track the reaction intermediates and products to better understand reaction mechanisms. 18,19 Previous studies demonstrate that the calcination temperature could significantly affect the photoelectrochemical performance of In 2 O 3 films by introducing different concentrations of oxygen vacancies.…”

Challenges Facing Sustainable Visible Light Induced Degradation of Poly- and Perfluoroalkyls (PFA) in Water: A Critical Review

“…A total 21 articles published since 2017 reporting on the solar and visible light-induced photocatalytic degradation of PFOA have been surveyed in this review (Figure ). The legendary photocatalyst, pristine-/modified-titanium dioxide (TiO 2 ), ,− and the photocorrosion resistant pristine-/modified-bismuth oxyhalide (BiOX) photocatalysts ,,,, equally share this investigation (5 publications each). The photocatalytic degradation of PFOA has been explored (4 publications) over photostable, modified indium oxide (In 2 O 3 ) photocatalysts. ,, Only a single article each on modified zinc oxide (ZnO) and bismuth oxide photocatalysts is reported.…”