Francesca Deganello

Perovskite-type oxides are among the most promising cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) due to their mixed ionic–electronic conductivity and compositional flexibility. Many high-performance cathodes rely on Sr substitution at the A-site, often associated with surface segregation and long-term degradation. In this work, we explore an alternative strategy based on defect engineering and phase interactions in Sr-free composites. Perovskite-fluorite composites based on LaFe_0.8Co_0.2O₃ were synthesized through a one-pot route designed to promote the formation of a perovskite phase and a limited amount of fluorite-type ceria. This approach allows the introduction of small fractions of Ce into the perovskite lattice, favoring the cooperative coexistence with La-doped CeO₂. Structural, microstructural and spectroscopic characterization indicates that Ce influences the crystallization pathway and composite defect chemistry. Variations in lattice parameters and Raman features suggest modifications of perovskite structure consistent with defect formation and lattice distortion. Reduction properties and electrical conductivity measurements indicate that Ce incorporation in the perovskite and oxide interaction affect charge transport and oxygen mobility. The electrochemical results demonstrate that the optimal trade-off between activation energy (Ea) and polarization resistance (Rp) is achieved for the sample, with a nominal cerium content, Ce/(La + Ce) of 0.16. Moreover, the electrochemical properties are found to correlate with the nominal cerium content, which regulates defect chemistry and the resulting composite composition. Overall, results suggest that the one-pot synthesis promotes beneficial interactions between the perovskite and ceria phases, allowing the development of Sr-free ferrite-based materials with enhanced functional properties, minimizing the amount of ceria in the composite.

This study reports the design, implementation, and descriptive evaluation of “Codici del Futuro”, a STEM-oriented education pathway developed by the Italian National Research Council (CNR) to promote students’ interest in science and awareness of research-related careers and addressed to local high school students. The programme involved 167 high school students organised in 10 groups and combined an orientation session with hands-on workshops delivered in CNR research facilities (chemistry, biotechnology, artificial intelligence, eXdended Reality/Augmented Reality (XR/AR), and game design). The chemistry workshop will be described as a case study. The study addresses two research questions: (RQ1) What group-level outcomes (participation, engagement, interest, behaviour) are observed across the multidisciplinary pathway? (RQ2) What post-activity satisfaction and short-term knowledge outcomes are observed in the chemistry workshop as an embedded case study? Group-level outcomes were assessed through a facilitator-based evaluation grid, using four single-item indicators rated on a 10-point scale and including field notes. The chemistry case study included an anonymous post-activity questionnaire (satisfaction, prior experience, and an eight-item knowledge test). Results documented high levels of engagement, interest, and appropriate behaviour across groups, whereas participation showed greater variability. In the chemistry case study, students reported high satisfaction and moderate post-activity knowledge scores, with differences across knowledge domains. Overall, findings provide descriptive evidence on student responses within a research-centre-based, multi-workshop STEM pathway.

Facing energy and environmental issues is recognized globally as one of the major challenges for sustainable development, to which sustainable chemistry can make significant contributions. Strontium ferrate-based materials belong to a little-known class of perovskite-type compounds in which iron is primarily stabilized in the unusual 4+ oxidation state, although some Fe³⁺ is often present, depending on the synthesis and processing conditions and the type and amount of dopant. When doped with cerium at the Sr site, the SrFeO_3−δ cubic structure is stabilized, more oxygen vacancies form and the Fe⁴⁺/Fe³⁺ redox couple plays a key role in its functional properties. Alone or combined with other materials, Ce-doped strontium ferrates can be successfully applied to wastewater treatment. Specific doping at the Fe site enhances their electronic conductivity for use as electrodes in solid oxide fuel cells and electrolyzers. Their oxygen storage capacity and oxygen mobility are also exploited in chemical looping reactions. The main limitations of these materials are SrCO₃ formation, especially at the surface; their low surface area and porosity; and cation leaching at acidic pH values. However, these limitations can be partially addressed through careful selection of synthesis, processing and testing conditions. This review highlights the high versatility and efficiency of cerium-doped strontium ferrates for energy and environmental applications, both at low and high temperatures. The main literature on these compounds is reviewed to highlight the impact of their key properties and synthesis and processing parameters on their applicability as sustainable thermocatalysts, electrocatalysts, oxygen carriers and sensors.

SrFeO ₃ ‐based oxides are multi‐functional ceramics belonging to the ABO ₃ ‐type perovskite family, where iron is interestingly present at the B‐site as Fe ⁴⁺ and partially reducible to Fe ³⁺ by doping strategies to tailor the physical–chemical properties. When doped, fine‐tuned SrFeO ₃ is exploitable in novel energy production systems, for example, electrocatalysts in intermediate temperature solid oxide fuel cells (IT‐SOFCs). This work aimed to evaluate how the B‐site composition and stoichiometry affect the functional properties of SrFeO ₃ ‐based materials when A‐site doping with cerium is fixed at 15 mol%. Hence, powdered samples were prepared by solution combustion synthesis, modulating the Fe/Co ratio or the B‐site stoichiometry (Fe + Co). From an in‐depth characterization, it was found that both B‐site nonstoichiometry and Fe/Co ratio influenced structure, redox properties, and electrochemical behavior. Still, nonstoichiometry played a major role in improving oxygen adsorption capacity and mobility, also thanks to the contribution of the segregated phases (CeO ₂ , Sr ₃ Fe ₂ O _{7− δ} ) generated by the induced B‐site unbalancing. The nonstoichiometric sample reached the highest oxygen reduction capability at the IT‐SOFC operating temperature (600°C) and the lowest activation energy (0.65 eV), whereas the cobalt‐rich sample showed poorer performance as an oxygen electrode. These results encourage further research on tunable cobalt‐poor and nonstoichiometric perovskites in energy‐related devices.

The well-being of the Earth and its inhabitants is compromised by the energy and climate crisis that has arisen from the prolonged and uncontrolled utilization of fossil fuels, which has caused a tremendous increase in anthropogenic CO₂ and a consistent depletion of natural energy resources

Metal-organic frameworks (MOFs) are emerging as promising materials for water purification membranes, owing to their uniform microporous structures and chemical functionalities. Here, we report a simple procedure for depositing MOF-based nanofiltration membranes on commercial TiO₂ ceramic tubular supports, completely avoiding the use of dispersants or binders. Zeolite imidazolate frameworks-8 (ZIF-8) nanocrystals were synthesized in methanol at room temperature and subsequently coated with an amorphous SiO₂-ZrO₂ gel to generate a dispersion of ZIF-8@SiO₂-ZrO₂ core-shell nanoparticles. The amorphous SiO₂-ZrO₂ gel served as a binding agent for the ZIF-8 nanocrystals, thus forming a defect-free continuous membrane layer. After repeating the coating twice, the active layer had a thickness of 0.96 μm, presenting a rejection rate >90% for the total organic carbon in an aquaculture effluent and in a wastewater treatment plant, while reducing the concentration of trimethoprim, here used as a target pollutant. Moreover, the oxide gel provided the MOF-based active layer with good adhesion to the support and enhanced its hydrophilicity, resulting in a membrane with excellent mechanical stability and resistance to fouling during the crossflow filtration of the real wastewater samples. These results implied the high potential of the MOF-based nanocomposite membrane for effective treatment of actual wastewater streams.

Access to clean water is limited by the increasing amount of persistent organic pollutants (POPs), since current methods fail to remove POPs completely. Therefore, new treatment technologies of surface water and wastewater are needed. In this study, two treatment methods are combined in one step, i.e., membrane filtration and thermocatalytic chemical oxidation of POPs. A perovskite‐type catalyst with formula Sr_0.85Ce_0.15FeO_3‐δ (SCF) is incorporated into an alumina membrane using a simple two‐step heat treatment to minimize any chemical reaction of the catalytic active perovskite with alumina. First, a sintering process under inert atmosphere, then, a heat‐treatment under oxidative conditions to oxidize the iron species in the perovskite structure. The well‐known thermocatalytic properties of SCF make the membrane thermocatalytic and thus able to degrade pollutants under dark conditions without addition of oxidants. The SCF content in the membrane is varied between 0 and 15 wt% to explore the change in membrane properties. Results demonstrate that the thermocatalytic membranes have great potential for continuous membrane filtration and simultaneous degradation of POPs. When considering methyl orange, up to 100% removal is obtained at room temperature, whereas up to 93% of bisphenol A is removed at temperatures approaching 60 °C.

SiO₂@TiO₂ core-shell nanoparticles were successfully synthesized via a simple, reproducible, and low-cost method and tested for methylene blue adsorption and UV photodegradation, with a view to their application in wastewater treatment. The monodisperse SiO₂ core was obtained by the classical Stöber method and then coated with a thin layer of TiO₂, followed by calcination or hydrothermal treatments. The properties of SiO₂@TiO₂ core-shell NPs resulted from the synergy between the photocatalytic properties of TiO₂ and the adsorptive properties of SiO₂. The synthesized NPs were characterized using FT-IR spectroscopy, HR-TEM, FE–SEM, and EDS. Zeta potential, specific surface area, and porosity were also determined. The results show that the synthesized SiO₂@TiO₂ NPs that are hydrothermally treated have similar behaviors and properties regardless of the hydrothermal treatment type and synthesis scale and better performance compared to the SiO₂@TiO₂ calcined and TiO₂ reference samples. The generation of reactive species was determined by EPR, and the photocatalytic activity was evaluated by the methylene blue (MB) removal in aqueous solution under UV light. Hydrothermally treated SiO₂@TiO₂ showed the highest adsorption capacity and photocatalytic removal of almost 100% of MB after 15 min in UV light, 55 and 89% higher compared to SiO₂ and TiO₂ reference samples, respectively, while the SiO₂@TiO₂ calcined sample showed 80%. It was also observed that the SiO₂-containing samples showed a considerable adsorption capacity compared to the TiO₂ reference sample, which improved the MB removal. These results demonstrate the efficient synergy effect between SiO₂ and TiO₂, which enhances both the adsorption and photocatalytic properties of the nanomaterial. A possible photocatalytic mechanism was also proposed. Also noteworthy is that the performance of the upscaled HT1 sample was similar to one of the lab-scale synthesized samples, demonstrating the potentiality of this synthesis methodology in producing candidate nanomaterials for the removal of contaminants from wastewater.

In situ grown perovskite and ceria biphasic system causes a structural distortion of the perovskite from cubic to tetragonal thus increasing oxygen availability and promoting the thermocatalytic activity in degradation of bisphenol A.