Perovskite photocatalysts for environmental remediation Mabel L. Day, Cameron J. Shearer Department of Chemistry, The University of Adelaide, South Australia, Australia Per- and polyfluoroalkyl substances (PFAS) are a ubiquitous class of stable, synthetic organic compounds that pose a significant threat to the health of humans and the environment. The fluorinated alkyl chain within PFAS molecules makes them impervious to environmental degradation and metabolic breakdown, exacerbating toxicity. There is a need to develop effective means of degradation. Complex metal oxides with a perovskite (ABO 3 ) structure, such as SrTiO 3 , are being investigated for photocatalytic water-splitting due to their unique photophysical properties. Aliovalent doping of Al 3+ into the B site within these structures replaces the Ti 4+ , thus preventing the self-reduction to Ti 3+ mid-gap states and reducing recombination rates. This method has been shown to enhance photocatalytic efficiency by >100-fold relative to un-doped samples 1 . Aliovalent doping as a form of defect engineering may prove pertinent to improving photocatalysis activity across a range of applications. This presentation will investigate the viability of transferring this technique to organic pollutant degradation, particularly PFAS. The effect of Al doping density on rates of photocatalysis using methyl orange as a model pollutant will be discussed, and results reported for a solid-state reaction of SrCO 3 and TiO 2 to yield SrTiO 3 , which then underwent a SrCl 2 flux-mediated reaction with AlO 3 to dope controlled amounts of Al into the perovskite structure. Conformation of these structures was obtained through X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Photocatalytic remediation of the model pollutant methyl orange showed a strong dependence on Al concentration. References 1. Ham, Y.; Hisatomi, T.; Goto, Y.; Moriya, Y.; Sakata, Y.; Yamakata, A.; Kubota, J.; Domen, K. Flux-Mediated Doping of SrTiO 3 Photocatalysts for Efficient Overall Water Splitting. Mater. Chem. A 2016 , 4 (8), 3027–3033.
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