01/07/2026: The article “Effects of Sc-doping and hydration on the band gap parameters of BaSnO3“(https://doi.org/10.1016/j.jssc.2026.125971) was published in the Journal of Solid State Chemistry. BaSnO3 is one of the materials prospective for high-temperature proton-conducting membranes. For that purpose, it is subjected to acceptor doping – BaSn1-xMxO3-δ (M = M3+ metal). This provides appearance of oxygen vacancies in the crystal structure allowing for further hydration and, consequently, proton conductivity. Such doping, oxygen vacancies formation, and hydration influence materials electronic properties in the vicinity of the band gap. However, for BaSnO3, as a proton conducting oxide, such effects have not been considered before. This work aims to experimentally and theoretically reveal changes in the band gap parameters of BaSn1-xScxO3-δ depending on the dopant concentration x and hydration. The results obtained indicate on strong concentration dependence of the band gap parameters, showing three distinct ranges: x ≤ 0.10, 0.15 ≤ x ≤ 0.20, and x ≥ 0.25. This effect arises mainly from redistribution of the Sn 5s- and Sc 3d-states in the conduction band. In general, Sc doping gradually increases the band gap of the BaSnO3 from 3.04 eV at x = 0 to 3.63 eV at x = 0.37. Effect of hydration is even more complex, with no changes of the band gap at x ≤ 0.10, and with transformation of the absorption edge shape and the band gap increase at x ≥ 0.15. Besides, absorption spectra of BaSnO3 show no typical for acceptor-doped oxides oxygen vacancy peak near the absorption edge. Thus, such behavior of BaSnO3 differs significantly from that for other similar proton-conducting perovskites, making it intriguing material for further deeper studies.
18/05/2026: The review “Heavily doped proton-conducting perovskites: Relationships between defect structure and functional properties” devoted to proton transport in acceptor-doped perovskite oxides was published in the journal Chimica Techno Acta (https://doi.org/10.15826/chimtech.9769). It identifies limitations inherent to conventional materials and explores the BaSn1–xInxO3–δ system. The latter is unique, since it can accommodate high indium concentrations while retaining cubic perovskite symmetry. The exceptional solid solution formation in this system allows for access to doping levels where oxygen vacancy concentrations exceed 0.2 per formula unit. This is a condition where defect-defect interactions are inevitable, and behavior may deviate qualitatively from that described by ideal solution models in the dilute limit. The present review establishes correlations between composition, average crystal structure, local atomic arrangements, defect structure, and various physicochemical and functional properties, such as hydration thermodynamics, proton conductivity, chemical expansion, and thermomechanical behavior. Particular attention is devoted to the heavily doped compositions (x = 0.4–0.7), where pronounced local structural disorder, composition-dependent trapping phenomena, and the interplay between thermal and chemical expansion effects significantly influence macroscopic transport behaviour. The combination of experimental and computational findings establishes a framework for understanding the relationships between structure and properties in highly defective proton-conducting perovskites.
05/05/2026: The article “Contemporary trends and frontiers in oxygen electrode design for protonic ceramic electrochemical cells: A scientometric perspective” (https://doi.org/10.1016/j.cej.2026.175380) was accepted for publication in the Chemical Engineering Journal. This review covers oxygen electrodes for protonic ceramic cells (PCCs). Low-temperature PCCs can be realized owing to improving ORR and OER processes. A combination of scientometric and scholarly analyses is successfully used. Scientometrics reveal the growth from fundamental discoveries to real applications. Analysis transforms 19 reviews into 15 strategies for next-gen PCC electrodes.
20/04/2026: In the Journal Analytica Chimica Acta will be published the results of investigation “A novel Ba1.15La1.85In2O7–δ-based amperometric sensor for hydrogen and steam analysis at reduced operating temperatures” (https://doi.org/10.1016/j.aca.2026.345289). The novelty of this work lies in the first application of a Ba1.15La1.85In2O7–δ -based electrochemical cell as a dual-function (H2/H2O) amperometric sensor validated under industrially relevant conditions (350–450 °C). This finding is significant as it provides a direct pathway for reliable in-situ analysis in complex streams. More broadly, this finding validates the potential shift from conventional single-perovskite electrolytes to new tailored material classes for electrochemical sensing. The results demonstrate that this material class enables a stable, linear, and selective responses, allowing the fabrication of high-performance amperometric-type sensors.
01/04/2026: The research “Band gap engineering in proton-conducting BaSn1–xInxO3–δ perovskites: Interplay of doping, hydration, and hydrogenation” (https://doi.org/10.1016/j.ceramint.2026.03.316) was accepted in the Ceramics International. Barium stannate BaSnO3 is a semiconducting oxide with cubic perovskite structure. It is capable for different types of doping, both in Ba and Sn sites, both by acceptor and donor dopants, allowing efficiently tuning its properties. Thus, BaSnO3 finds numerous applications, and its usage as a proton conducting ceramic electrolytes is one of them. Recently, it was reported that In-doped BaSn1–xInxO3–δ shows outstanding properties, like ability to form wide range of solid solutions up to x = 0.65, good chemical stability and high proton conductivity. However, this material lacks data on its band gap parameters, but given the semiconducting nature of barium stannate these data is crucial for comprehensive understanding of its functional properties. Therefore, this work is aimed at elucidating changes in the band gap parameters of BaSn1–xInxO3–δ promoted by doping and proton incorporation by hydration and hydrogenation. The results obtained indicate on systematic decrease of the band gap Eg with In concentration, from 3.04 eV at x = 0 to 2.76 eV at x = 0.6, which is suggested to be due to replacement of the Sn 5s states by In 5s. Besides, there is transformation of the absorption edge shape at x > 0.4 arising from substantial oxygen non-stoichiometry. Hydration leads to increase of Eg, and the higher the x, the greater the Eg change. However, that nature of this effect is not yet clear. Simultaneously, as oxygen sublattice becomes complete, the absorption edge shape restores to initial state. Effect of hydrogenation is more complex, leading to strong local tetragonal/orthorhombic distortions at x ≤ 0.2 and even phase decomposition at x ≥ 0.4. All this behavior of In-doped BaSnO3 diverges from typical trends observed in classical wide-gap proton conductors, such as doped LaScO3, BaZrO3, SrTiO3, and SrZrO3, thus, requiring a special attention.
17/03/2026: In the International Journal of Hydrogen Energy was publeshed the article “Are the ohmic and polarization resistances of solid oxide electrochemical cells independent from each other?” (https://doi.org/10.1016/j.ijhydene.2026.154040). Solid oxide electrochemical cells (SOCs) operating at low and intermediate temperatures represent a promising technology for efficient and environmentally friendly energy conversion. The performance of these cells is predominantly governed by their total area specific resistance, which comprises two principal components: the ohmic resistance (associated with ionic transport within the electrolyte) and the polarization resistance (originating from electrode reaction kinetics). Consequently, the rational design of high-performance SOCs necessitates the independent optimization of these resistive contributions. It is generally accepted that ohmic and polarization resistances are intrinsic properties of the electrolyte and electrodes, respectively, and can thus be controlled separately through material doping or microstructural engineering of the corresponding components. However, the electrolyte and electrode materials form a common area (interface), indicating their close relation to each other. In the present study, a simple experiment was conducted to confirm the relationship between ohmic and polarization resistances. In detail, several symmetrical cells were prepared using the same electrode material and various electrolytes. It was shown that the polarization resistance of the electrode was as low as higher ionic conductivity of the electrolytes under identical experimental conditions. The obtained results are further discussed within the broader context of literature data for protonic ceramic fuel and electrolysis cells, revealing a commonality: the performance of the electrode is not an isolated property but is intrinsically linked to the characteristics of the electrolyte with which it interfaces.
16/02/2026: Original Research Report “Remarkably high hydration capability of BaSn1–xInxO3–δ perovskite materials: What do we need to know about protons in complex oxides?” (https://doi.org/10.1016/j.matre.2025.100382) was published in the Materials Reports: Energy. Proton-conducting oxides constitute a wide class of materials that exhibit pronounced proton transport in humid atmospheres. Owing to their high proton mobility, these oxides are regarded as promising electrolytes for low- and intermediate-temperature protonic ceramic fuel cells and electrolysis cells, which offer efficient and clean energy conversion. Protons appear in complex oxides through a dissociative water adsorption process, which consists of the interaction between existing oxygen vacancies and water molecules in the gas phase. This process is also known as hydration or water uptake. Within the present work, we analyze the hydration features of BaSn1–xInxO3–δ perovskite materials (BSIx), which include a wide range of solid solutions (0 ≤ x < 0.7) and a nearly theoretical hydration limit for almost all studied compounds at the same time. The latter is a unique property of In-doped stannates, which is untypical for most other proton-conducting oxides. Along with the experimental data on the water uptake of BSIx, we provide an in-depth investigation of proton concentrations depending on external factors, involving a further comparison with literature data on materials hydration, as well as the discovery of hidden relationships between proton concentration and various functional properties. Therefore, this work contributes to theoretical and applied investigations of proton-conducting oxides, especially in the context of their hydration behavior.
15/01/2026: In the Journal Solid State Sciences was published the article “Ba and La co-doped Pr2NiO4+δ materials: Relationships between defect structure, thermal, and electrochemical properties” (https://doi.org/10.1016/j.solidstatesciences.2025.108130). Layered nickelate phases represent a convenient matrix for designing complex oxides intended for high-temperature applications. This study examines the structural, electrical, and electrochemical properties of the novel Pr1.8–xLaxBa0.2NiO4+δ (x = 0.0–0.8) materials as potential air electrodes for reversible solid oxide cells (rSOCs). Additionally, we attempted to study the hydration ability of these materials. These materials are based on the Ruddlesden-Popper phase, Pr2NiO4+δ, which is known for its mixed ionic-electronic transport behavior and favorable oxygen-diffusion characteristics. Substituting praseodymium with lanthanum and barium partially enhances the phase stability and optimizes the defect chemistry, improving the electrochemical performance of the designed electrodes. Compared with traditional perovskite and Ruddlesden-Popper cathode materials, the proposed electrode materials demonstrate superior surface oxygen exchange kinetics and thermal stability, positioning them as promising candidates for long-term rSOC applications.
