Cerium and Titanium-doped Strontium Ferrate activity in photo(thermo)-catalytic dye removal

Background and aims ABO3 perovskites are a mixed oxide family of versatile compounds, finding wide application in several sectors, including environmental protection. Herein, a SrFeO3-δ, bearing the peculiar Iron oxidation state Fe(IV), is the starting compound for doped compositions with Cerium and Titanium at A- and B-sites, respectively, to fine-tune physical-chemical features and catalytic behavior.1 Previous studies demonstrated that Ce-doped Strontium Ferrates’ activity in wastewater remediation could be triggered by light or mild temperatures.2 These excitation sources are now employed with Sr0.85Ce0.15Fe1-xTixO3-δ (SC15FT) for dyes’ abatement. Methods SC15FT powders were prepared through citric acid-assisted Solution Combustion Synthesis, followed by calcination and washing.3,4 The characterizations adopted were TOC, N2 adsorption at 77K (BET, BJH models), XRD+Rietveld refinement, and SEM. SC15FT application included photocatalytic processes upon simulated solar light and dark thermocatalysis (~60 °C) for the degradation of Orange II and Rhodamine B, while monitoring the adsorption phenomena. Material performance was compared to reference Sr0.85Ce0.15FeO3-δ (SC15F) systems. Results Results from XRD (extent of CeO2 segregation out of the perovskite nanostructure and cell parameters) and textural investigations showed a non-negligible impact of Iron replacement by Titanium. Similarly, catalytic activity was affected: compared to SC15F, preliminary results showed that Titanium induced lower photo(thermo)-catalytic Orange II removal, but similar photobleaching level and moderately higher thermal-induced action were revealed against Rhodamine B (Fig.1).