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Lithium‐sulfur batteries face challenges like polysulfide shuttle and slow conversion kinetics, hindering their practical applications in renewable energy storage and electric vehicles. Herein, a solution to solve this issue is reported by using a cation vacancy engineering strategy with rational synthesis of La‐deficient LaCoO3 (LCO‐VLa). The introduction of cation vacancies in LCO‐VLa modifies the geometric structure of coordinating atoms, exposing Co‐rich surface with more catalytically active surfaces. Meanwhile, the d‐band center of LCO‐VLa shifts toward the Fermi level, enhancing polysulfide adsorption. Furthermore, multivalent cobalt ions (Co3+/Co4+) induced by charge compensation enhance the electrical conductivity of LCO‐VLa, accelerating electron transfer processes and improving catalytic performance. Theoretical calculations and experimental characterizations demonstrate that La‐deficient LCO‐VLa effectively suppresses the polysulfide shuttle, reduces the energy barrier for polysulfide conversion, and accelerates redox reaction kinetics. LCO‐VLa‐based batteries demonstrate exceptional rate performance and cycling stability, retaining 70% capacity after nearly 500 cycles at 1.0 C, with a minimal decay rate of 0.055% per cycle. These findings highlight the significance of cation vacancy engineering for exploring precise structure‐activity relationships during polysulfides conversion, facilitating the rational design of catalysts at the atomic level for lithium‐sulfur batteries. [ABSTRACT FROM AUTHOR]

The oxide surface structure plays a vital role in controlling and utilizing the emergent phenomena occurring at the interface of nanoarchitecture. A complete understanding of ternary oxide surfaces remains challenging due to complex surface reconstructions in various chemical and physical environments. Here a thermodynamic framework is developed to treat the stability of ternary oxide surfaces with finite temperature and chemical environments. Strontium titanate, as a representative ternary oxide, is used to establish the complete energy landscape of SrTiO3 (001) surface. The complete mapping yields a comprehensive understanding of various stable SrTiO3 surfaces with finite temperature and chemical potential or vapor pressure of the constituents, i.e., Sr (or Ti) metal and oxygen. This treatment also reveals a stable surface unknown yet with SrTi2O3 stoichiometry, which unveils the missing link between numerous previous experimental observations and the current understanding of SrTiO3 surface. Interestingly, the new surface shows an anisotropic surface‐localized metallic state originating from the characteristic surface structure. The findings would provide a viable way to understand ternary oxide surfaces and further utilize SrTiO3 surfaces for oxide nanoarchitectures. [ABSTRACT FROM AUTHOR]

Reversible protonic ceramic electrochemical cell (R-PCEC) is a new energy conversion device that can achieve efficient conversion between chemical energy and electrical energy. However, the oxygen electrode has poor activity towards oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which hinders the large-scale application of R-PCEC. Therefore, in order to improve the catalytic activity of oxygen electrodes, La 0.5 Sr 0.5 Co 0.2 Fe 0.8 O 3 (LSCF) is prepared using mesoporous silica SiO 2 (SBA-15) and polymethyl methacrylate (PMMA) as templates, and it was combined with BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY) to form a composite oxygen electrode for R-PCEC. Compared to the LSCF with solid-state reaction method, LSCF with hard-template method shows higher specific surface area and more oxygen vacancy, resulting in excellent ORR catalytic activity. In addition, LSCF prepared using PMMA as a template exhibits the best ORR catalytic activity, and the single cell with this composite oxygen electrode shows the highest maximum power density of 406 mW cm−2 in fuel cell (FC) mode with wet H 2 (3%H 2 O) and air as the fuel and oxidant, respectively. Additionally, it demonstrates a current density of −973 mA cm−2 at 1.3 V in electrolysis cell (EC) mode with wet air (10%H 2 O) as the oxidant. The single cell also shows good reversibility in FC mode and EC mode. This work provides a new strategy to improve the bifunctional activity of oxygen electrode in R-PCEC. [ABSTRACT FROM AUTHOR]

Oxygen evolution and reduction reactions (OER and ORR) play crucial roles in energy conversion processes such as water splitting and air batteries, where spin dynamics inherently influence their efficiency. However, the specific contribution of spin has yet to be fully understood. In this study, we intentionally introduce a spin channel through the transformation of trigonal antiferromagnetic SrCoO2.5 into cubic ferromagnetic SrCoO3, aiming to deepen our understanding of spin dynamics in catalytic reactions. Based on the results from spherical‐aberration‐corrected microscopy, synchrotron absorption spectra, magnetic characterizations, and density functional theory calculations, it is revealed that surface electron transfer is predominantly governed by local geometric structures, while the presence of the spin channel significantly enhances the bulk transport of spin‐polarized electrons, particularly under high current densities where surface electron transfer is no longer the limiting factor. The overpotential for OER is reduced by at least 70 mV at 150 mA cm−2 due to the enhanced conductivity from spin‐polarized electrons facilitated by spin channels, with an expectation of even more significant reductions at higher current densities. This work provides a clearer picture of the role of spin in oxygen‐involved electrocatalysis, providing critical insights for the design of more efficient catalytic systems in practical applications. [ABSTRACT FROM AUTHOR]

Exploring semiconductor materials with enhanced photocatalytic activity is essential for practical applications. This review provides a comprehensive overview of the photocatalytic reaction mechanisms. The discussion highlights recent progress in perovskite oxide materials for various environmental and energy applications, including H2/O2 production, organic pollutant degradation, heavy metal removal, radionuclide removal, CO2 reduction, and N2 fixation. The structural characteristics of perovskite oxides including titanates, tantalates, niobates, ferrites, and complex perovskite oxides are discussed, focusing on current strategies to enhance their photocatalytic activity. Furthermore, recent advances in the design and development of perovskite-based photocatalytic reactors are reviewed, emphasizing their potential for increased efficiency and practical implementation. This review aims to provide insights into the abilities, research gaps, future perspectives, and recommendations for further studies of perovskite oxide photocatalysts in addressing significant environmental and energy challenges. [ABSTRACT FROM AUTHOR]

Developing highly efficient catalysts for oxygen evolution reactions (OER) in complex water environments is crucial for promoting the photovoltaic electrolysis of water splitting for hydrogen production in arid areas. However, traditional catalysts often exhibit limitations in terms of reaction kinetics and electrode corrosion resistance. In this work, we successfully prepared a self-supporting perovskite complex oxide La0.7Sr0.3CoO3-δ/NF (LSC/NF) catalyst by means of simple hydrothermal synthesis combined with programmed annealing, and successfully applied to OER reaction in oilfield wastewater. In alkaline oilfield wastewater, at a current density of 10 mA cm−2, LSC/NF requires only 411 mV of overpotential, which is lower than that of LSC (493 mV) and traditional catalyst RuO2 (451 mV), suggesting a high OER catalytic activity. The good electrocatalytic activity can be attributed to its superhydrophilicity, increased electrochemical active surface area, faster reaction kinetics and higher oxygen vacancy concentration. This research offers valuable new insights for the development of OER electrocatalysts with high catalytic activity in complex water systems in arid areas. A self-supporting perovskite oxide catalyst La0.7Sr0.3CoO3-δ/NF was synthesized by a simple process combining hydrothermal and annealing. The growth of perovskite oxide nanosheets directly on the conductive nickel foam matrix gives the catalyst a strong hydrophilicity and significantly expands its electrochemical active surface area, thus enhancing the OER activity of LSC/NF in oilfield wastewater. [ABSTRACT FROM AUTHOR]

Perovskite oxide semiconductor is unique for its capability to form epitaxial heterostructures with both dielectric and metallic perovskite oxides. The study underscores the potential of perovskite oxides for multi‐layer stacking, a key aspect in advancing semiconductor technology as silicon‐based devices evolve toward 3D stacked structures. Fabrication of the first double‐level double‐gate field‐effect transistors (DL DG‐FETs) is demonstrated, where each layer is epitaxially grown using all‐perovskite oxides. This resulted in improvements in subthreshold swing, current drivability, and field effect mobility. This innovation not only highlights the distinctive potential of perovskite oxides but also provides new avenues for integration with other perovskite oxides on Si for more advanced electronic functions. [ABSTRACT FROM AUTHOR]

Orthorhombic perovskite GdFeO3 nanostructures are promising materials with multiferroic properties. In this study, a new low‐temperature plasma‐assisted approach is developed via dual anodic dissolution of solid metallic precursors for the preparation of perovskite GdFeO3 nanoparticles (NPs) that can be collected both as colloids as well as deposited as a thin film on a substrate. Two solid metallic foils of Gd and Fe are used as precursors, adding to the simplicity and sustainability of the method. The formation of the orthorhombic perovskite GdFeO3 phase is supported by high‐resolution transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman measurements, while a uniform elemental distribution of Gd, Fe, and O is confirmed by energy dispersive X‐ray spectroscopy, proving the successful preparation of ternary compound NPs. The magnetic properties of the NPs show zero remnant magnetization typical of antiferromagnetic materials, and saturation at high fields that can be caused by spin interaction between Gd and Fe magnetic sublattices. The formation mechanism of ternary compound NPs in this novel plasma‐assisted method is also discussed. This method is also modified to demonstrate the direct one‐step deposition of thin films, opening up opportunities for their future applications in the fabrication of magnetic memory devices and gas sensors. [ABSTRACT FROM AUTHOR]

The development of multi-functional and highly mixed ionic-electronic conductive perovskite oxide-based electrodes is becoming an established trend for designing and developing SOFC/SOEC reversible cells. Ideally, the same material can be employed at both electrodes provided that structural stability, high conductivity and catalytic activity are preserved in different operational atmospheres. Here, controlled Fe substitution with a small extent (0.5 mol%) of platinum at the B-site of a lanthanum strontium ferrite is proposed as an effective method to enhance the original oxide properties as both air and fuel electrode for solid oxide cells. The effects of low Pt-doping on La 0.6 Sr 0.4 FeO 3-δ structure, morphology and electrocatalytic activity are investigated and discussed. La 0.6 Sr 0.4 Fe 0.995 Pt 0.005 O 3-δ (05P-LSF) is first tested as air electrode, displaying lower area specific resistance as compared to the Pt-free perovskite. 05P-LSF structural stability and conductivity are assessed in 100 % CO 2 and 50 % CO 2 –50 % CO environments. Symmetric devices are then tested as SOECs in 100 % CO 2 , obtaining a current density output of 1.08 A/cm2 at 1.5 V. Electrochemical impedance spectroscopy (EIS) with distribution of relaxation times analysis (DRT) are used to provide insights on the electrode operation. Pt nanoparticle exsolution at the fuel electrode is induced by voltage application. The device stability under applied voltage is assessed for over 120 h. SOFC/SOEC characterization in a 50 % CO 2 /50 % CO mixture at 850 °C is also provided, obtaining a maximum power density of 270 mW/cm2 in SOFC mode, and a current density of 0.91 A/cm2 at 1.5 V in SOEC mode. [ABSTRACT FROM AUTHOR]

The preparation of highly active, rare earth, non-platinum-based catalysts for hydrogen evolution reactions (HER) in alkaline solutions would be useful in realizing green hydrogen production technology. Perovskite oxides are generally regarded as low-active HER catalysts, owing to their unsuitable hydrogen adsorption and water dissociation. In this article, we report on the synthesis of Li2ZrO3 perovskites substituted with samarium and terbium cations at A-sites for the HER. LSmZrO3 (LSmZO) and LTbZrO3 (LTbZO) perovskite oxides are more affordable materials, starting materials in abundance, environmentally friendly due to reduced usage of precious metal and moreover have potential for several sustainable synthesis methods compared to commercial Pt/C. The surface and elemental composition of the prepared materials have been confirmed by X-ray photoelectron spectroscopy (XPS). The morphology and composition analyses of the LSmZO and LTbZO catalysts showed spherical and regular particles, respectively. The electrochemical measurements were used to study the catalytic performance of the prepared catalyst for hydrogen evolution reactions in an alkaline solution. LTbZO generated 2.52 mmol/g/h hydrogen, whereas LSmZO produced 3.34 mmol/g/h hydrogen using chronoamperometry. This was supported by the fact that the HER electrocatalysts exhibited a Tafel slope of less than 120 mV/dec in a 1.0 M alkaline solution. A current density of 10 mA/cm2 is achieved at a potential of less than 505 mV. The hydrogen production rate of LTbZO was only 58.55%, whereas LSmZO had a higher Faradaic efficiency of 97.65%. The EIS results demonstrated that HER was highly beneficial to both electrocatalysts due to the relatively small charge transfer resistance and higher capacitance values. [ABSTRACT FROM AUTHOR]

Strontium aluminate, with suitable lattice parameters and environmentally friendly water solubility, has been strongly sought for use as a sacrificial layer in the preparation of freestanding perovskite oxide thin films in recent years. However, due to this material's inherent water solubility, the methods used for the preparation of epitaxial films have mainly been limited to high-vacuum techniques, which greatly limits these films' development. In this study, we prepared freestanding single-crystal perovskite oxide thin films on strontium aluminate using a simple, easy-to-develop, and low-cost chemical full-solution deposition technique. We demonstrate that a reasonable choice of solvent molecules can effectively reduce the damage to the strontium aluminate layer, allowing successful epitaxy of perovskite oxide thin films, such as 2-methoxyethanol and acetic acid. Molecular dynamics simulations further demonstrated that this is because of their stronger adsorption capacity on the strontium aluminate surface, which enables them to form an effective protective layer to inhibit the hydration reaction of strontium aluminate. Moreover, the freestanding film can still maintain stable ferroelectricity after release from the substrate, which provides an idea for the development of single-crystal perovskite oxide films and creates an opportunity for their development in the field of flexible electronic devices. [ABSTRACT FROM AUTHOR]

Sulfur is a promising anion dopant for exploring exotic physical phenomena in complex perovskite oxides. However, sulfurization to the epitaxial single-crystal oxide thin films with high crystallinity is experimentally challenging due to the volatility of sulfur element; thus, sulfurization effects on the associated properties have been scarcely studied. Here, we demonstrate an enhancement of ferroelectric polarization of epitaxial BaTiO3 thin films by sulfur doping. Initially, the epitaxial BaTiO3 thin films with high crystallinity were grown by pulsed laser deposition (PLD). Then, sulfurization to epitaxial BaTiO3 films was performed using a precursor of thiourea (CH4N2S) solution via a spin-coating technique. The crystalline structure of sulfurized BaTiO3 films was identified by X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The structural distortion with the elongated out-of-plane lattice constant was observed in the sulfurized BaTiO3 films. Atomic force microscopy (AFM) analyses also confirmed the surface morphology of films after sulfurization. Interestingly, we found an enhanced ferroelectric polarization in sulfur-doped BaTiO3 films accompanying the improved tetragonality in the crystal structure after sulfurization. The increments in the remnant (~34.8%) and saturated (~30.6%) polarizations of sulfurized BaTiO3 films were obtained in comparison with pure BaTiO3 films. Our work could be a primary study for a thorough understanding of the sulfur doping effect in perovskite oxides, opening up the potential of oxysulfide materials.

Controlling the in-plane magnetocrystalline anisotropy and interfacial exchange coupling between ferromagnetic (FM) layers plays a key role in next-generation spintronic and magnetic memory devices. In this work, we explored the effect of tuning the magnetocrystalline anisotropy of La2/3Sr1/3CoO3 (LSCO) and La2/3Sr1/3MnO3 (LSMO) layers and the corresponding effect on interfacial exchange coupling by adjusting the thickness of the LSCO layer (tLSCO). The epitaxial LSCO/LSMO bilayers were grown on (110)o-oriented NdGaO3 (NGO) substrates with a fixed LSMO (top layer) thickness of 6 nm and LSCO (bottom layer) thicknesses varying from 1 to 10 nm. Despite the small difference (∼0.2%) in lattice mismatch between the two in-plane directions, [001]o and [11̅0]o, a pronounced in-plane magnetic anisotropy was observed. Soft X-ray magnetic circular dichroism hysteresis loops revealed that for tLSCO ≤ 4 nm, the easy axes for both LSCO and LSMO layers were along the [001]o direction, and the LSCO layer was characterized by magnetically active Co2+ ions that strongly coupled to the LSMO layer. No exchange bias effect was observed in the hysteresis loops. In contrast, along the [11̅0]o direction, the LSCO and LSMO layers displayed a small difference in their coercivity values, and a small exchange bias shift was observed. As tLSCO increased above 4 nm, the easy axis for the LSCO layer remained along the [100]o direction, but it gradually rotated to the [11̅0]o direction for the LSMO layer, resulting in a large negative exchange bias shift. Therefore, we provide a way to control the magnetocrystalline anisotropy and exchange bias by tuning the interfacial exchange coupling between the two FM layers.

In this work, we present theoretical calculations of the structural, electronic, optical and thermoelectric properties of the perovskite oxides LaMO3 (M = Ga or In) using density functional theory (DFT) with GGA–PBE approximation, as implemented in the ABINIT code. The cubic crystal structure of LaMO3 (M = Ga or In) compounds changes and its volume increases when the Ga atom is replaced by an In atom. In addition, negative formation energies suggest the thermodynamic stability of the studied compounds. Electron charge densities reveal an ionic bond between La and O, while the bond between M and O appears covalent. Electronic properties showed the indirect semiconducting behavior of LaGaO3 and LaInO3 perovskites. The calculated indirect bandgaps Eg (R–Γ) are found to be 3.34eV for LaGaO3 and 2.08eV for LaInO3. In addition, optical characteristics are determined in terms of real ε1(ω) and imaginary ε2(ω) parts of dielectric constant ε(ω), refractive index n(ω), absorption coefficient α(ω), reflectivity R(ω), energy loss function L(ω), optical conductivity σ(ω) and transmittance T(ω) are also studied. Optical absorption of light energy has been observed in both the visible and ultraviolet ranges, increasing the importance of the studied materials for optoelectronic applications. Finally, the thermoelectric performance of LaMO3 (M = Ga or In) materials has been explored using the Boltzmann transport theory implemented in the BoltzTraP software package. [ABSTRACT FROM AUTHOR]

The reforming reactions of greenhouse gases require catalysts with high reactivity, coking resistance, and structural stability for efficient and durable use. Among the possible strategies, exsolution has been shown to demonstrate the requirements needed to produce appropriate catalysts for the dry reforming of methane, the conversion of which strongly depends on the choice of active species, its interaction with the support, and the catalyst size and dispersion properties. Here, we exploit the exsolution approach, known to produce stable and highly active nanoparticle-supported catalysts, to develop iridium-nanoparticle-decorated perovskites and apply them as catalysts for the dry reforming of methane. By studying the effect of several parameters, we tune the degree of exsolution, and consequently the catalytic activity, thereby identifying the most efficient sample, 0.5 atomic % Ir-BaTiO3, which showed 82% and 86% conversion of CO2 and CH4, respectively. By comparison with standard impregnated catalysts (e.g., Ir/Al2O3), we benchmark the activity and stability of our exsolved systems. We find almost identical conversion and syngas rates of formation but observe no carbon deposition for the exsolved samples after catalytic testing; such deposition was significant for the traditionally prepared impregnated Ir/Al2O3, with almost 30 mgC/gsample measured, compared to 0 mgC/gsample detected for the exsolved system. These findings highlight the possibility of achieving in a single step the mutual interaction of the parameters enhancing the catalytic efficiency, leading to a promising pathway for the design of catalysts for reforming reactions. [ABSTRACT FROM AUTHOR]

Developing efficient O2 electrocatalyst is crucial for lithium-oxygen (Li-O2) batteries (LOBs). Among various catalysts, perovskite oxides have exhibited diverse catalytic activity owing to their low synthetic cost, tunable constitutions, flexible structures and excellent electrochemical stability. In this research, LaNi0.5Fe0.5O3 perovskites (LNFO) were synthesized via a classical sol–gel route combined with succedent calcination treatment. The ORR and OER tests indicate that the catalytic activity of LNFO calcined at 600 (LNFO-1) and 800℃ (LNFO-3) is superior to that of 700 (LNFO-2) and 900℃ (LNFO-4). To determine which sample is more suitable as a catalyst for LOBs, the LOBs with LNFO-1 and LNFO-3 electrodes were assembled. The LNFO-1 cathode shows discharge capacity of 1.7686 mAh under the current density of 100 mA g−1, which is higher than that with LNFO-3 cathode. The initial discharge–charge profiles of LOBs with LNFO-1 and LNFO-3 electrodes under a cutoff capacity of 1 mAh at 100 mA g−1 indicates that a lower overpotential could gained from LNFO-1 electrode. Meanwhile, 233 and 93 cycles can be realized under capacity limit of 0.15 and 0.315 mAh, respectively, at the current density of 100 mA g−1. The results demonstrate a lower overpotential, and longer circularity can be implemented in the LOB with LNFO-1 cathode, which can be put down to the larger specific surface area, and more presence of Ni3+ and Fe4+ in LNFO-1. Therefore, our work confirmed that the mesoporous LNFO-1 is a promising electrocatalyst for LOBs. [ABSTRACT FROM AUTHOR]

A domain‐resolved synchrotron single‐crystal X‐ray diffraction study of a LaAlO3 pseudo‐merohedral twin crystal was successfully carried out in combination with powder diffraction data from the same sample. Multiscale structure information ranging from micro‐ to nano‐ to atomic scale was determined from one single crystal. There is almost no change of domain ratios at temperatures of less than 400 K indicating no movement of the domain wall. The changes in domain ratio indicating domain‐wall movement were observed in the temperature range of 450 to 700 K, which is consistent with the result of the previous mechanical measurement. It is also found that the ratio of four twin components becomes equal (25%), just below phase transition temperature. These findings are important for domain engineering and theoretical studies related to LaAlO3. The temperature dependence of domain ratio was preserved in the heating and cooling cycle except for the first heating process to 840 K. Therefore, the domain structure after heating to 840 K is intrinsic to the crystal. Accurate structure parameters were determined through unit‐cell parameter calibration and domain‐resolved structure analysis. The method for calibration of unit‐cell parameters from twin crystal data was derived and used to solve the inconsistent unit‐cell parameters between single crystal and powder data in the present and previous studies. [ABSTRACT FROM AUTHOR]

In this study, lanthanum ferrites with strontium and magnesium-doped perovskite-type structures intended for energy storage were developed. Sr and Mg-doped lanthanum ferrites are constructed using the citrate auto-combustion dry gel technique. Several analytical tools were used to characterize the doped materials. Because the stabilization of mass loss happened above this temperature and no phase transformation was seen from thermo gravimetric analysis, the calcination procedure was carried out at 450 °C. The X-ray diffraction data has confirmed the existence of a single powder phase in the air-sintered materials and the mixing of the powdered phases during the calcination process. The presence of agglomerated sheets in the samples was revealed by scanning electron microscopy. The LSFM samples exhibit weak ferromagnetic interactions, according to the VSM analysis of the magnetization curve and the hysteresis loops. The electrochemical impedance spectroscopy showed that the 20% strontium and magnesium samples had better conductivity. These findings suggest that increasing the Sr and Mg content increases sample conductivity while decreasing the activation energy of the conduction process. As a result, the perovskite oxides synthesized in this study have the potential to be cathodes for supercapacitors and magnetic devices. [ABSTRACT FROM AUTHOR]

Perovskite oxides, renowned for their adaptable structure and optoelectronic characteristics, hold significant potential for applications in catalysis and photoelectrochemical (PEC) processes. In this research, the preparation of praseodymium iron oxide (PrFeO3) by spin coating and the impact of incorporating a calcium (Ca) dopant on its PEC efficacy as photocathodes are investigated. Spin coating of a polymer containing sol–gel yields thin films with uniform morphology and porosity, facilitating effective semiconductor/electrolyte interactions, as characterized by scanning electron microscopy analyses. Evaluation of transient photocurrent responses reveals that introducing Ca at a 5 at% doping level significantly enhances the PEC activity of PrFeO3, resulting in an optimal photocurrent of −124 μA cm−2 at +0.43 V vs. a reversible hydrogen electrode (VRHE) under simulated sunlight conditions. This enhancement is accompanied by an incident photon‐to‐current efficiency (IPCE) of 3.8% at +0.43 VRHE and 350 nm, along with an onset potential of +1.1 VRHE. Ultraviolet and visible spectroscopy analyses indicate an increase in light‐absorption capabilities in the Ca‐doped films and a noticeable reduction in bandgap compared to the undoped counterparts, further supported by IPCE measurements. In the findings, the significant role of dopants in augmenting the photocurrent performance of stable perovskite oxides, highlighting their potential in advancing photon conversion technologies, is underscored. [ABSTRACT FROM AUTHOR]

The reverse water‐gas shift (RWGS) reaction serves as a critical pathway for converting CO2 into diverse chemicals. The Mars–van Krevelen (MvK) mechanism, which leverages lattice oxygen as the oxidant and oxygen vacancies as reductants, offers an alternative catalytic strategy for the selective RWGS reaction. While Mn‐substituted SrTiO3 (i. e., SrTi0.8Mn0.2O3) has been shown to promote the RWGS reaction selectively via the MvK mechanism, achieving a sufficient conversion of CO2 necessitates elevated temperatures. This study investigated the effect of Pd‐loaded SrTi0.8Mn0.2O3 on the activation of adsorbed H2 molecules, which generated oxygen vacancies and enhanced CO2 conversion. Notably, 1.0 wt % Pd‐loaded SrTi0.8Mn0.2O3 yielded 13.4 % of CO at 673 K, whereas pristine SrTi0.8Mn0.2O3 and Pd‐loaded SrTiO3 yielded negligible or minimal amount of CO. Hydrogen temperature‐programmed reduction and X‐ray absorption spectroscopy measurements revealed that Pd promoted the formation of oxygen vacancies via both thermodynamic and kinetic mechanisms. Fourier transform infrared spectroscopy and kinetic studies revealed that the RWGS reaction over Pd‐loaded SrTi0.8Mn0.2O3 proceeded primarily via the MvK mechanism with a partial contribution from the Langmuir–Hinshelwood mechanism. This study underscores the effectiveness of combining metal and MvK‐type catalysts to enhance the efficiency of the RWGS reaction. [ABSTRACT FROM AUTHOR]

Sulfur is a promising anion dopant for exploring exotic physical phenomena in complex perovskite oxides. However, sulfurization to the epitaxial single-crystal oxide thin films with high crystallinity is experimentally challenging due to the volatility of sulfur element; thus, sulfurization effects on the associated properties have been scarcely studied. Here, we demonstrate an enhancement of ferroelectric polarization of epitaxial BaTiO3 thin films by sulfur doping. Initially, the epitaxial BaTiO3 thin films with high crystallinity were grown by pulsed laser deposition (PLD). Then, sulfurization to epitaxial BaTiO3 films was performed using a precursor of thiourea (CH4N2S) solution via a spin-coating technique. The crystalline structure of sulfurized BaTiO3 films was identified by X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The structural distortion with the elongated out-of-plane lattice constant was observed in the sulfurized BaTiO3 films. Atomic force microscopy (AFM) analyses also confirmed the surface morphology of films after sulfurization. Interestingly, we found an enhanced ferroelectric polarization in sulfur-doped BaTiO3 films accompanying the improved tetragonality in the crystal structure after sulfurization. The increments in the remnant (~34.8%) and saturated (~30.6%) polarizations of sulfurized BaTiO3 films were obtained in comparison with pure BaTiO3 films. Our work could be a primary study for a thorough understanding of the sulfur doping effect in perovskite oxides, opening up the potential of oxysulfide materials. [ABSTRACT FROM AUTHOR]

The rare earth-based perovskite oxides are vastly studied for optoelectronic and photovoltaic applications. Here in this manuscript, the structural, mechanical, thermodynamic, electronic, and optical properties of AcXO3 (X = Al, Ga, In) are addressed by density functional theory (DFT) based WIEN2k code. The optimized parameters are reported from the Birch–Murnaghan equation of states in terms of lattice constant and bulk modulus. The elastic constants C11, C12, and C44 for the cubic phase satisfy the Born–Huang stability conditions. The Poisson and Pugh's ratios discriminate that the Ac(Al/Ga)O3 have brittle and AcInO3 ductile nature. The thermodynamic parameters like melting temperature, Debye temperature, and lattice thermal conductivity have also been explained in terms of elastic constants and moduli. The electronic behavior is explained by the band structures and density of states which is mainly contributed by Ac-d, X-p, and O-p states. The replacement of Al with Ga, and In reduces the bandgap from 4.1 to 2.2 eV. The optical characteristics are studied in terms of dielectric constants, absorption coefficient, reflection, refractive index, optical loss, and their dependent parameters. The absorption region shifts from ultraviolet to the visible region making them significant for diverse optoelectronic applications. [ABSTRACT FROM AUTHOR]

The effect of Pd doping on the NOx removal efficiency and NH 3 selectivity was studied over lean NOx trap LaCo 1- x Pd x O 3 -Ba/Al 2 O 3 -type catalysts. Two catalysts were prepared by the sequential impregnation of 15 wt% of LaCo 1- x Pd x O 3 -type perovskites and 20 wt% of barium over alumina. The results of X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, temperature programmed techniques, UV–vis diffuse reflection absorption spectroscopy, and X-ray photoelectron spectroscopy demonstrated that perovskite and barium grains uniformly distribution over the alumina surface. Cobalt partial substitution by palladium changed the chemical coordination environment, thus leading to the redox properties of perovskites getting different. Moreover, the LaCoO 3 –Ba/Al 2 O 3 catalyst exhibited a high reduction on NOx by H 2 between 450 and 550 °C. Whereas Pd-doped LaCo 0·9 Pd 0·1 O 3 –Ba/Al 2 O 3 catalyst decreased the best activity interval around 100 °C, as well as improved the NH 3 selectivity. The NOx reduction conversion of the LaCo 0·9 Pd 0·1 O 3 –Ba/Al 2 O 3 catalyst increased significantly from 72.9% to around 100% at H 2 /NO ratio = 1, and the production of NH 3 was increased from 20.1% to 58.6% at H 2 /NO ratio = 3. • Novel perovskite-based catalysts were synthesized for excellent textural properties. • Pd changes the chemical environment of the cobalt metal ions and enhances the redox properties of LaCoO 3. • Pd enhances H 2 dissociation thus offering more H ions to promote the NH 3 generation. [ABSTRACT FROM AUTHOR]

Here, we successfully synthesized Sr-doped perovskite-type oxides of La1−xSrxCo1−λO3−δ, "LSX" (x = 0, 0.1, 0.3, 0.5, 0.7), using the glycine-assisted solution combustion method. The effect of strontium doping on the catalyst structure, NO to NO2 conversion, NOx adsorption and storage, and NOx reduction performance were investigated. The physicochemical properties of the catalysts were studied by XRD, SEM-EDS, N2 adsorption–desorption, FTIR, H2-TPR, O2-TPD, and XPS techniques. The NSR performance of LaCoO3 perovskite was improved after Sr doping. Specifically, the perovskite with 50% of Sr doping (LS5 sample) exhibited excellent NOx storage capacity within a wide temperature range (200–400 °C), and excellent stability after hydrothermal and sulfur poisoning. It also displayed the highest NOx adsorption–storage capacity (NAC: 1889 μmol/g; NSC: 1048 μmol/g) at 300 °C. This superior performance of the LS5 catalyst can be attributed to its superior reducibility, better NO oxidation capacity, increased surface Co2+ concentration, and, in particular, its generation of more oxygen vacancies. FTIR results further revealed that the LSX catalysts primarily store NOx through the "nitrate route". During the lean–rich cycle tests, we observed an average NOx conversion rate of over 50% in the temperature range of 200–300 °C, with a maximum conversion rate of 61% achieved at 250 °C. [ABSTRACT FROM AUTHOR]

Oxide perovskites (ABO3) have fascinated researchers due to their potential applications in diverse fields because of their flexible chemistry and favourable characteristics including tunable band gap, high carrier mobility, and excellent optical properties. Here, a DFT-based study was conducted on RbTaO3, delved into the material behaviour under varying stress ranging from 0 to 100 GPa, emphasizing its potential for advanced applications. Key findings include a reduction in the lattice parameter from 4.2084 to 3.8149 Å, and volume from 74.5334 to 55.5200 Å3, along with a band gap narrowing from 1.574 to 1.490 eV. Additionally, DOS analysis gives an understanding of the electronic transitions involving Rb-5s, Ta-5d, and O-2p states. Optically, the material showed high absorption, conductivity, and lower loss function. The mechanical stability is confirmed by Born stability criteria through elastic constants (C11, C12, and C44). Further assessments using Poisson's ratio, Pugh's ratio (B/G), Frantsevich ratio, Cauchy pressure (CP), and anisotropic factor underscore its ductility and define anisotropic behaviour. The upward trend in phonon dispersion denotes its thermal resilience. From a thermodynamic perspective, the studied material exhibits superior high-temperature stability under high-stress levels, as confirmed by Debye temperature (θD). Furthermore, an inverse association of enthalpy and total entropy with free energy was observed. Comprehensive analysis of RbTaO3 under varying stress provides valuable insights and highlights its potential in electronics, advanced materials engineering, and high-temperature applications. [ABSTRACT FROM AUTHOR]

Abstract The oxide surface structure plays a vital role in controlling and utilizing the emergent phenomena occurring at the interface of nanoarchitecture. A complete understanding of ternary oxide surfaces remains challenging due to complex surface reconstructions in various chemical and physical environments. Here a thermodynamic framework is developed to treat the stability of ternary oxide surfaces with finite temperature and chemical environments. Strontium titanate, as a representative ternary oxide, is used to establish the complete energy landscape of SrTiO3 (001) surface. The complete mapping yields a comprehensive understanding of various stable SrTiO3 surfaces with finite temperature and chemical potential or vapor pressure of the constituents, i.e., Sr (or Ti) metal and oxygen. This treatment also reveals a stable surface unknown yet with SrTi2O3 stoichiometry, which unveils the missing link between numerous previous experimental observations and the current understanding of SrTiO3 surface. Interestingly, the new surface shows an anisotropic surface‐localized metallic state originating from the characteristic surface structure. The findings would provide a viable way to understand ternary oxide surfaces and further utilize SrTiO3 surfaces for oxide nanoarchitectures.

Here, we successfully synthesized Sr-doped perovskite-type oxides of La1−xSrxCo1−λO3−δ, “LSX” (x = 0, 0.1, 0.3, 0.5, 0.7), using the glycine-assisted solution combustion method. The effect of strontium doping on the catalyst structure, NO to NO2 conversion, NOx adsorption and storage, and NOx reduction performance were investigated. The physicochemical properties of the catalysts were studied by XRD, SEM-EDS, N2 adsorption–desorption, FTIR, H2-TPR, O2-TPD, and XPS techniques. The NSR performance of LaCoO3 perovskite was improved after Sr doping. Specifically, the perovskite with 50% of Sr doping (LS5 sample) exhibited excellent NOx storage capacity within a wide temperature range (200–400 °C), and excellent stability after hydrothermal and sulfur poisoning. It also displayed the highest NOx adsorption–storage capacity (NAC: 1889 μmol/g; NSC: 1048 μmol/g) at 300 °C. This superior performance of the LS5 catalyst can be attributed to its superior reducibility, better NO oxidation capacity, increased surface Co2+ concentration, and, in particular, its generation of more oxygen vacancies. FTIR results further revealed that the LSX catalysts primarily store NOx through the “nitrate route”. During the lean–rich cycle tests, we observed an average NOx conversion rate of over 50% in the temperature range of 200–300 °C, with a maximum conversion rate of 61% achieved at 250 °C.

Designing an electrocatalyst with low Pt content is an immediate need for essential reactions in low temperature fuel cell systems. In the present work, La0.9925Ba0.0075Al0.995Pt0.005O3 is aimed at using with low (only 0.5%) Pt doping as an electrocatalyst for oxygen reduction reaction (ORR). The low doping level renders exsolution of 1–2 nm nanoparticles with uniform dispersion upon reduction in H2/N2 at low temperatures. Pt exsolved perovskite oxides deliver significantly enhanced catalytic activity for ORR and improved stability in alkaline media. This study demonstrates that LaAlO3 with low noble metal content holds immense potential as an electrocatalyst in real fuel cell systems. [ABSTRACT FROM AUTHOR]

Symmetric solid oxide electrolysis cells (SSOECs) are widely studied because they can simplify the preparation process and save costs. In this study, high-performance symmetric electrode material La 0.5 Sr 0.5 Fe 0.8 Ni 0.1 Nb 0.1 O 3-δ (LSFNiNb) is proposed. A heterogeneous structure with high catalytic activity is constructed via in-situ exsolution of Ni–Fe alloy nanoparticles (NPs). LSFNiNb shows the highest electrical conductivity of 157 S cm−1 in the air at 650 °C. In an atmosphere of 5% H 2 –95% N 2 , the polarization impedance is 0.302 Ω cm2 at 800 °C. While the current density is 0.767 A cm−2 in 60% CO 2 –20% H 2 O-20% H 2 , at 800 °C and 1.5 V. In addition, there is no significant degradation in SOEC mode at a current density of 0.2 A cm−2 for 110 h. • Efficient and stable symmetrical electrodes are used for H 2 O/CO 2 co-electrolysis. • In-situ exsoluted Ni–Fe alloy nanoparticles enhance the electrochemical performance. • A current density of 0.767 A cm−2 at 1.5 V in co-electrolysis mode is achieved. • The cell shows an excellent stability performance for 110 h. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV)‐sensitive semiconductors play a key role in converting UV light into electric signals in a UV photodetector. Two‐dimensional (2D) oxide perovskite, as a kind of green and stable semiconductor materials, exhibits excellent UV detection capabilities. However, the non‐dense nanosheet thin film induces alternative shunts in vertical‐structured devices results in high ohmic leakage currents. Large number of oxygen vacancies in 2D oxide perovskite leads to the adsorption / desorption process of oxygen molecules that slows down the device's response speed. Therefore, an inorganic–organic heterojunction that effectively fills up the pinholes in nanosheet films, effectively suppressing the dark current of the device by 100 000 times are designed. Meanwhile, the construction of inorganic–organic heterojunctions can accelerate the charge carriers' transporting process, resulting in a fast rise / decay response time of 0.7 ms / 8.5 ms. Moreover, the inorganic–organic heterojunction endows the device with excellent self‐powered performance, presenting a high responsivity of 60 mA W−1. This photodetector demonstrates application potential in a UV communication system with a detection angle of 30 degrees and a close‐range communication of 1.2 m. [ABSTRACT FROM AUTHOR]

The practical utilization of TiO2 as a semiconductor in dye-sensitized solar cells (DSSCs) has been set back by poor visible light absorption, high charge carrier recombination, and low electrical conductivity, which reduce the power conversion efficiency (PCE) and sustainability of the device. In this respect, perovskites with excellent properties, such as large surface area, good optical properties, high electrical conductivity, and superior electrochemical stability, have recently emerged as promising alternatives capable of overcoming the drawbacks of TiO2. Herein, Sr0.7Sm0.3Fe0.4Co0.6O2.65 (SSFC) perovskites were prepared via the ball milling method at various milling times of 0, 5, and 10 h, and the obtained samples were denoted by SSFC-0, SSCF-5, and SSCF-10, respectively. Increasing the ball milling time led to a significant reduction in nanoparticle size and agglomeration, which, in turn, increased the surface area and electrical conductivity of the samples. As a consequence, the SSFC-10 perovskite exhibited the smallest average particle sizes (18.9 nm) with the largest surface area (61.8 m2 g−1) and minimum defects, which allowed for efficient electron transport, resulting in the best electrical conductivity of 49.8 S cm−1. Ultimately, DSSCs fabricated using SSFC-10 semiconductor layers achieved an optimum PCE of 6.01 %, which is an improvement of 8.67 %, 1.1 %, and 6.56 % for SSFC-0 (3.69 %), SSFC-5 (4.96 %), and TiO2 (5.64 %), respectively. Thus, varying the ball milling time can be used as an effective technique to tailor the physicochemical properties of SSFC to suit desired applications, particularly the fabrication of highly efficient and sustainable DSSC semiconductor layers.

Electrochemical ammonia synthesis is being widely investigated to couple with renewable electricity for future sustainable ammonia production. Protonic ceramic electrochemical cells (PCECs) possess superior energy transfer efficiency and remarkable flexibility to produce high-demand chemicals such as H2, CH4, and NH3 from readily available feedstocks (e.g., H2O, CO2, N2). Despite recent advances that have been established, the research for the high-efficiency PCECs for practical ammonia synthesis continues. In this review, we summarized the recent progress of PCECs for ammonia synthesis. First, we briefly introduce the basic mechanisms and protocols of the ammonia synthesis. Then, we systemically introduce the cell configurations, representative electrolytes and electrodes of PCECs for the ammonia synthesis. We highlight the strategies to tune the ion/electron mobility and the catalytic performance, which are related to the defect structures and redox properties of the electrolyte/electrode, and the opportunities for next-generation ammonia synthesis. Finally, perspectives on ammonia synthesis in PCECs are proposed consering the current challenges.

Strontium aluminate, with suitable lattice parameters and environmentally friendly water solubility, has been strongly sought for use as a sacrificial layer in the preparation of freestanding perovskite oxide thin films in recent years. However, due to this material’s inherent water solubility, the methods used for the preparation of epitaxial films have mainly been limited to high-vacuum techniques, which greatly limits these films’ development. In this study, we prepared freestanding single-crystal perovskite oxide thin films on strontium aluminate using a simple, easy-to-develop, and low-cost chemical full-solution deposition technique. We demonstrate that a reasonable choice of solvent molecules can effectively reduce the damage to the strontium aluminate layer, allowing successful epitaxy of perovskite oxide thin films, such as 2-methoxyethanol and acetic acid. Molecular dynamics simulations further demonstrated that this is because of their stronger adsorption capacity on the strontium aluminate surface, which enables them to form an effective protective layer to inhibit the hydration reaction of strontium aluminate. Moreover, the freestanding film can still maintain stable ferroelectricity after release from the substrate, which provides an idea for the development of single-crystal perovskite oxide films and creates an opportunity for their development in the field of flexible electronic devices.

As the photoactive TiO 2 film in dye-sensitized solar cells (DSSCs) is transparent to incident light owing to its nano-sized particles, the efficiency may be affected by the light loss. Therefore, light scattering layers including CeMnO 3 , CeFeO 3 , CeSnO 3 , CeZnO 3 , 3D-hexagonal mesoporous silica (HMS-3), and HMS-3:CeMnO 3 composites were deposited on TiO 2 layer by doctor blade technique in order to harvest more sunlight. To characterize each material, XRD, FTIR, PL, DRS, FESEM, EDS, and BET analyses were investigated. In addition, dye absorption capacity, power conversion efficiency (PCE), open-circuit voltage decay (OCVD), and charge transfer parameters were assessed. According to photovoltaic data, TiO 2 /50 wt% HMS-3+50 wt% CeMnO 3 based DSSC brought about the maximum PCE of 7.47% with fill factor (FF), short-circuit current density (J sc), and open-circuit voltage (V oc) of 0.48, 21.17 mA/cm2, and 0.738 V, respectively, displaying 75.4% higher PCE compared to solar cell fabricated by TiO 2 (PCE = 4.26%, J sc = 11.72, V oc = 0.685 V, FF = 0.53). The champion 50 wt% HMS-3+50 wt% CeMnO 3 composite featured large particles with high porosity, which could enhance light scattering and cause the light path to be longer, based on the Mie theory. Moreover, because of the big surface area (643.80 m2/g), large pore volume (0.4282 cm3/g), and appropriate N719 dye loading of the champion 50 wt% HMS-3+50 wt% CeMnO 3 composite, more dye molecules were excited, and the number of light-generated electrons was boosted, elevating the current density, facilitating faster charge transfer from the TiO 2 photoanode towards the Pt electrode, and limiting electron-hole recombination to a high extent, which led to an enormous improvement in efficiency. [Display omitted] • Scattering layers were designed for photoanodes of dye-sensitized solar cells (DSSCs). • Perovskite oxides CeMnO 3 , CeFeO 3 , CeSnO 3 , and CeZnO 3 were synthesized for DSSCs. • Various 3D-hexagonal mesoporous silica (HMS-3)/perovskite composites were prepared. • HMS-3 and best HMS-3/CeMnO 3 composite had surface areas of 878.60, 643.80 m2/g. • The champion DSSC with 50 wt% HMS-3+50 wt% CeMnO 3 indicated PCE = 7.47%. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrogen oxidation reaction (NOR) offers an efficient and sustainable approach for conversion of widespread nitrogen (N2) into high‐value‐added nitrate (NO3−) under mild conditions, representing a promising alternative to the traditional approach that involves harsh Haber–Bosch and Ostwald oxidation processes. Unfortunately, due to the weak absorption/activation of N2 and the competitive oxygen evolution reaction, the kinetics of NOR process is extremely sluggish accompanied with low Faradaic efficiencies and NO3− yield rates. In this work, an oxygen‐vacancy‐enriched perovskite oxide with nonstoichiometric ratio of strontium and ruthenium (denoted as Sr0.9RuO3) was synthesized and explored as NOR electrocatalyst, which can exhibit a high Faradaic efficiency (38.6 %) with a high NO3− yield rate (17.9 μmol mg−1 h−1). The experimental results show that the amount of oxygen vacancies in Sr0.9RuO3 is greatly higher than that of SrRuO3, following the same trend as their NOR performance. Theoretical simulations unravel that the presence of oxygen vacancies in the Sr0.9RuO3 can render a decreased thermodynamic barrier toward the oxidation of *N2 to *N2OH at the rate‐determining step, leading to its enhanced NOR performance. [ABSTRACT FROM AUTHOR]

With the rapid development of novel energy conversion and storage technologies, there is a growing demand for enhanced performance in a wide range of electrocatalysts. Perovskite oxides (ABO3) have caused widespread concerns due to their excellent electrocatalytic properties, low cost, stable and reliable performance. In recent years, the research on anion O‐site doping of perovskite oxides has been a cynosure, which is considered as a promising route for enhancing performance. However, a systematic review summarizing the research progress of anion‐doped perovskite oxides is still lacking. Therefore, this review mainly introduces the elements and strategies of various common anions doped at O‐site of perovskite oxides, analyzes their influence on the physical and chemical properties of perovskites, and separately concludes their applications in electrocatalysis. This review will provide ideas and prospects for the development of subsequent anion doping strategies for high performance perovskite oxides. [ABSTRACT FROM AUTHOR]

Herein, the substitution of Mn in SrTiO3 is presented as an effective approach to develop functional ferromagnets with spin‐polarized semiconductive band dispersions. The task is performed with the full‐potential linearized augmented planewave (FP‐LAPW) approach based on density functional theory (DFT) as coded in WIEN2k. Exchange and correlation effects are taken into account using generalized gradient approximation (GGA). The strong hybridization between O‐2p and Mn‐3d is accountable for the origin of the semiconductive ferromagnetic ground state in Sr1−xMnxTiO3 (x = 12.5%, 25%, 50%, and 75%). Increase in Mn content in SrTiO3 crystal causes a significant increase in total magnetic moment values. The optical behavior is investigated by computing refractive index, optical conductivity, dielectric constant, absorption coefficient, and reflectivity within 0–10 eV energy range. Mn‐doped SrTiO3 shows maximum absorption in the ultraviolet region. The computed physical characteristics suggest a potential usage of Sr1−xMnxTiO3 in optoelectronic and magnetic devices. [ABSTRACT FROM AUTHOR]

Reversible protonic ceramic electrochemical cells (R-PCECs) are ideal, high-efficiency devices that are environmentally friendly and have a modular design. This paper studies BaFe0.6Zr0.1Y0.3O3−δ (BFZY3) as a cobalt-free perovskite oxygen electrode for high-performance R-PCECs where Y ions doping can increase the concentration of oxygen vacancies with a remarkable increase in catalytic performance. The cell with configuration of Ni-BZCYYb/BZCYYb/BFZY3 demonstrated promising performance in dual modes of fuel cells (FCs) and electrolysis cells (ECs) at 650 °C with low polarization resistance of 0.13 Ω cm2, peak power density of 546.59 mW/cm2 in FC mode, and current density of − 1.03 A/cm2 at 1.3 V in EC mode. The alternative operation between FC and EC modes for up to eight cycles with a total of 80 h suggests that the cell with BFZY3 is exceptionally stable and reversible over the long term. The results indicated that BFZY3 has considerable potential as an air electrode material for R-PCECs, permitting efficient oxygen reduction and water splitting. [ABSTRACT FROM AUTHOR]

Ferromagnetic insulator plays a pivotal role in various emerging spintronic effects and can be integrated as an essential component into future spintronic devices. However, ferromagnetic insulating perovskite oxides are rather scarce due to the strong coupling between ferromagnetism and metallicity via double exchange and superexchange mechanisms, severely restricting the development for oxide-based spintronic devices. Here, the disorder of manganite La2/3Sr1/3MnO3 (LSMO) films grown on MgAl2O4 substrates is utilized to decouple ferromagnetism and metallicity, thereby inducing a ferromagnetic insulating state over a rather broad temperature and thickness range. These films are non-crystalline with enormous disorder. The films with thicknesses less than 16 nm are in completely insulating state, and the films with thicknesses larger than 16 nm are in essentially insulating state with high resistivity. This insulating state is ascribed to the disorder in LSMO films and can be fitted by a localization model. In contrast, all LSMO films exhibit ferromagnetic transitions with considerable saturated magnetic moments and the Curie temperatures near room temperature, leading to the ferromagnetic insulator phase in our manganite heterostructures over a large temperature and thickness interval. Our results broaden the mind for inducing new ferromagnetic insulating state for potential applications in spintronic devices.

Perovskite solar cells (PSC) have emerged as highly efficient photovoltaic devices, boasting remarkable power conversion efficiencies (PCE) exceeding 25.5%. However, the incorporation of perovskite films raises environmental concerns due to associated toxicity, and PSC deteriorates over time due to material breakdown accelerated by heat, moisture, and undesired chemical reactions at interfaces. For example, employing titanium dioxide TiO₂ as the electron transport layer (ETL) and the organic semiconductor Spiro-OMeTAD as the hole transport layer (HTL) can lead to instability in the device. The broad bandgap of TiO₂ leads to charge carrier recombination in ETL, undermining device performance, along with the high cost and complex synthesis of Spiro-OMeTAD. Researchers have investigated several methods to tackle these challenges, including altering the interfacial structure and employing adaptable materials between the charge-gathering electrode and perovskite active layers. Due to their extensive bandgap and notable electron mobility, perovskite oxides are highly attractive; however, these materials encounter difficulties such as clustering, which can cause short circuits and leakage current. They also suffer from inefficient charge separation, surface hydrophilicity, and inadequate absorption of visible light. Furthermore, the addition of graphene particles to both compact and mesoporous TiO₂ layers, which act as electron-selective layers, aims to lower series resistance and boost electron extraction efficiency, achieving a peak PCE of 26.3%. These materials have garnered attention for their outstanding optoelectronic properties, superior stability, and non-toxic characteristics. This review extensively delves into the integration of graphene-based materials as interfacial layers and how that will affect the performance of PSC in terms of stability and efficiency.

Abstract With the rapid development of novel energy conversion and storage technologies, there is a growing demand for enhanced performance in a wide range of electrocatalysts. Perovskite oxides (ABO3) have caused widespread concerns due to their excellent electrocatalytic properties, low cost, stable and reliable performance. In recent years, the research on anion O‐site doping of perovskite oxides has been a cynosure, which is considered as a promising route for enhancing performance. However, a systematic review summarizing the research progress of anion‐doped perovskite oxides is still lacking. Therefore, this review mainly introduces the elements and strategies of various common anions doped at O‐site of perovskite oxides, analyzes their influence on the physical and chemical properties of perovskites, and separately concludes their applications in electrocatalysis. This review will provide ideas and prospects for the development of subsequent anion doping strategies for high performance perovskite oxides.

The electronic, optical, structural, elastic, and mechanical properties of cubic Strontium Hafnium Oxide SrHfO3 under variable stress conditions were examined using the Generalized Gradient Approximation (GGA) method. Density functional theory was employed to determine the influence of stress on the electronic properties of the oxide perovskite, resulting in changes in the electronic band gap 3.206–2.834 eV, partial density of states, and total density of states. Significant variations in various optical properties, including absorption, conductivity, reflectivity, as well as the real and imaginary components of the dielectric function, were observed. The differences were noted in the loss function and refractive index. The elastic properties revealed a linear increase in elastic constants such as C11 and C12, while C44 showed a declining trend. Likewise, an increase in mechanical properties, including Young's modulus, bulk modulus, and shear modulus, was found. Furthermore, variations were discovered in the Frantsevich ratio, Anisotropy, Poisson's ratio, and Pugh's ratio. These findings provided valuable intuitions into the properties of cubic SrHfO3, with potential implications for the development of semiconducting devices, thermal coatings, and dielectrics.

LaMn 0.3 Co 0.7 O 3-δ Perovskite nanofibers with oxygen-deficient structure have been used as dual-function oxygen catalysts for rechargeable zinc-air batteries with high high specific capacity of 811.54 mAh g−1 and good cycling stability. [Display omitted] The development and design of efficient bifunctional electrocatalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for rechargeable Zinc-air batteries (ZABs). Optimizing the d-band structure of active metal center in perovskite oxides is an effective method to enhance ORR/OER activity by accelerating the rate-determining step. Herein, we report a deficient method to optimize the d-band structure of Co ions in LaMn 0.3 Co 0.7 O 3-δ (LMCO-2) perovskite nanofibers, which regulates the mutual effect between B-site Co ions and reactive oxygen intermediates. It is proved by experiment and theoretical calculation that the d-band center (M d) of transition metal ions in LMCO-2 is moved up and the electron filling number of e g orbital in B site is 1.01, thus leading to the reduction of Gibbs free energy required for ORR rate-determining step (OH*→H 2 O*) to 0.22 eV and promoting reaction proceeds. In this manner, LMCO-2 showed good bifunctional oxygen electrocatalytic activity, with a half-wave potential of 0.71 V vs. RHE. Furthermore, the high specific capacity of 811.54 mAh g−1 and power density of 326.56 mW cm−2 were obtained by using LMCO-2 as the cathode catalyst for ZABs. This study proved the feasibility of d-band structure regulation to enhance the electrocatalytic activity of perovskite oxides. [ABSTRACT FROM AUTHOR]