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Author
Baami González, Xavier
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Abstract
“Concentrate-and-degrade” is an effective strategy to promote the adsorption and degradation of pollutants in photocatalytic systems. New and suitable adsorptive photocatalysts are required to build efficient and cost-effective solutions for the new strategy.
This study presents a proof-of-concept as well as an optimization of working parameters for BEA zeolites and Fe-BEA zeolites as adsorptive photocatalysts, to effectively degrade perfluorooctanoic acid (PFOA). Fe-BEA 360 exhibited excellent PFOA adsorption (>99% in 30 min), photodegradation (98% in 4 h), and mineralization (50% in 4 h) under optimal conditions (25ºC, pH 5.9, 1 atm, 1.0 g/L catalyst, 1.0 mg/L PFOA, UV-light irradiation at 254 nm).
The introduction of Fe into the zeolite highly improved the performance allowing the binding of the carboxylic head group of PFOA to Fe3+. Furthermore, the presence of iron enables direct electron transfer due to a ligand-to-metal charge transfer. Fe-BEA 360 was amenable to repeated uses in four consecutive adsorption-photodegradation cycles. The reported results showed the capabilities of metal-doped BEA zeolites as adsorptive photocatalysts for PFOA adsorption and photodegradation.
Finally, the study incorporates diverse synthesis proofs-of-concept for diverse BEA zeolites and composite materials that include the coupling of diverse photocatalysts and zeolites, and the design of a magnetic zeolite.
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