The impact of Eu3+ doping at the Sr2+ and Sn4+ sites in SrSnO3 on its structural and electronic properties was studied and correlated with the photocatalytic efficiency. The compounds were synthesized using a modified Pechini method. Refinement of the synchrotron X-ray diffraction (S-XRD) data showed that the samples had an orthorhombic Pbnm symmetry. The incorporation of Eu into the lattice led to increased short- and long-range disorder, inducing additional distortion in the SnO6. XANES measurements revealed that mixed Eu valences (Eu3+ and Eu2+) were present in Eu-doped samples, and DFT calculations confirmed the presence of these ions at Sr2+/Sr4+ sites in the SrSnO3, resulting in changes in the electronic behavior. The catalytic performance toward Remazol yellow dye photodegradation and the catalysts’ surface properties were also evaluated. The catalytic efficiency followed the order of Sr­(Sn0.99Eu0.01)­SnO3 > (Sr0.99Eu0.01)­SnO3 > SrSnO3. The order was clearly related to selected-site doping that changed the degree of the inter- and intraoctahedral distortion and the introduction of different Eu midgap states, which apparently favor charge separation upon photoexcitation during photocatalysis. The results shown here are of great importance to the functionalization of SrSnO3 and other perovskite materials by lanthanoid ions, especially Eu3+, for effective applications as photocatalysts.

This work aimed to study the influence of seven hybrid functionals (B3LYP, B1WC, B3PW, PBE0, PBESOL0, SOGGAXC, and WC1LYP) and selected basis sets in the CRYSTAL software library on the calculated structural, electronic, mechanical, and vibrational properties of BaSnO 3 under the framework of periodic density functional theory. Based on the results showing the best approximation of the experimental band gap energy and lattice parameter, the PBE0 functional and the Baranek basis set were used to optimize the outer valence shell functions, α sp and α d , in order to improve the quality of calculated properties. An analysis was done to determine the density of states, band structure, elastic constants, and infrared (IR) active modes. The results were compared with other reported quantum mechanical calculations and available experimental data.

DFT calculation applied to K4Nb6O17 allowed to identify and correlate its electronic and vibrational properties with [NbO6] intraoctahedral distortion.

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