Solution combustion synthesis of novel PrFeO3/CeO2 nanocomposite with enhanced photo-Fenton activity under visible light.

In this study, we successfully synthesized PrFeO 3 /CeO 2 -based nanocomposites with different mass contents of СeO 2 (0–18 wt%) via solution combustion with subsequent heat treatment in air. The results of EDXS and PXRD confirmed the presence of two phases in nanocomposites: a PrFeO 3 orthorhombic phase with an average crystallite size of 13.6–36.6 nm and a СeO 2 cubic phase in the form of an ultradisperse phase with an average particle size of 7.4–11.5 nm depending on the mass content of СeO 2. We characterized the morphology, porosity, and specific surface structure of the powders by scanning electron microscopy, transmission electron microscopy, and adsorption–structural analysis, which established the foam-like morphology of nanopowders with a predominantly mesoporous structure. The specific surface area varied in the range of 8.8–19.4 m2/g for different СeO 2 contents. We studied the optoelectronic properties of the nanocomposites with UV–visible diffuse reflection spectroscopy, which determined the values of the band gap of the PrFeO 3 phase actively absorbing radiation in the visible region (2.07–2.13 eV). Based on the adsorption–photocatalytic properties of the obtained nanocomposites, we established the presence of a synergistic effect from the addition of CeO 2 to PrFeO 3. We studied the adsorption capacity of the samples during the adsorption of methyl violet, and we analyzed the resulting adsorption isotherm in accordance with the Freundlich model. The obtained results indicated increased dye adsorption in the presence of CeO 2 , with the maximum value of K f = 45.7 observed at 15 wt%. We studied the photocatalytic Fenton-like activity of nanopowders during the degradation of methyl violet under the influence of visible light. We established he presence of a positive effect of CeO 2 additive. At 9 wt% content, the maximum photocatalytic reaction rate constant was reached at 0.056 min−1, which was previously unavailable for analogical Fenton-like photocatalysts based on REE orthoferrites. Based on the conducted studies, we propose a possible mechanism of the photo-Fenton-like decomposition of organic pollutants in the presence of PrFeO 3 /CeO 2 under the influence of visible light. The obtained nanocomposite materials were also characterized by high cyclic stability and the potential for magnetically controlled separation from the reaction solution, showing their potential as a basis for photocatalysts in wastewater treatment from dyes and other organic pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]