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Cation-anion co-doping has proven to be an effective method of improving the photocatalytic performances of CaTiO3 perovskites. In this regard, (La/Ce-N/S) co-doped CaTiO3 models were investigated for the first time using first-principles calculations based on a supercell of 2 × 2 × 2 with La/Ce concentrations of 0.125, 0.25, and 0.375. The energy band structure, density of states, charge differential density, electron-hole effective masses, optical properties, and the water redox potential were calculated for various models. According to our results, (La-S)-doped CaTiO3 with a doping ratio of 0.25 (LCOS1-0.25) has superior photocatalytic hydrolysis properties due to the synergistic performances of its narrow band gap, fast carrier mobility, and superb ability to absorb visible light. Apart from the reduction of the band gap, the introduction of intermediate energy levels by La and Ce within the band gap also facilitates the transition of excited electrons from valence to the conduction band. Our calculations and findings provide theoretical insights and solid predictions for discovering CaTiO3 perovskites with excellent photocatalysis performances. [ABSTRACT FROM AUTHOR]

Insulating oil plays a crucial role in internal insulation of oil-impregnated transformers. It has been demonstrated in a variety of experimental studies that mineral oil (MO) and vegetable oil (VO) can be blended in different ratios to improve insulation properties; however, the mechanisms underlying this phenomenon remain unclear. In this study, a molecular dynamics (MD) simulation approach was used to investigate diffusion of water molecules in VO/MO blends and dielectric constants of a mixture. The results show that the diffusion coefficient of water molecules is negatively correlated with the proportion of VO; thus, addition of VO helps to improve the insulation properties of a mixture. Due to introduction of strong polar functional groups, a decrease in the diffusion behavior of water molecules can be attributed to an increase in the interaction energy and formation of hydrogen bonds between water molecules and the mixed oil system. There is a direct correlation between the dielectric constant of a mixture and VO content; however, it is very sensitive to water content. The presence of strong polar water molecules or functional groups in a mixture leads to an increase in the dielectric constant, which results in a reduction in insulating properties. Accordingly, presence of polar groups plays an important role in determining the insulating properties of a mixture. To increase the insulation performance of a mixture, it is important to consider the diffusion-inhibiting and dielectric effects of the stronger polar groups in vegetable oil compared to those in mineral oil. [ABSTRACT FROM AUTHOR]

High catalytic performances of metal-semiconductor heterostructures have gained significant attention in recent years. However, developing fast and low-cost synthesis of multiphase heterojunction catalysts has long been a challenge. Herein, three phases of Cu-CeO 2 -SrTiO 3-δ heterojunction catalyst are successfully synthesized by combining with sol-gel and rapid plasma exsolution method. Using dielectric barrier discharge plasma (DBD), Cu nanoparticles are exsolved and uniformly distributed on the surface of CeO 2 -SrTiO 3-δ. This unique multiphase heterojunction catalyst exhibits superior performance in photothermal reverse water gas shift (RWGS) reactions. The yield of CO from this catalyst is impressive at 11.32 mmol g−1 h−1, 9 times greater than pure SrTiO 3 , and the selectivity for CO is high (99.95%). The enhanced activity is primarily attributed to the synergistic effect resulting from the incorporation of three phases of Cu nanoparticles, CeO 2 , and SrTiO 3-δ , as well as their interfaces. The increase in oxygen vacancy sites in CeO 2 enhances the adsorption of CO 2 , whereas the doping and exsolution of Cu help to broaden the light absorption range. A significant role is played by the localized surface plasmon resonance (LSPR) effect of Cu nanoparticles in promoting the catalytic performance of RWGS. This study demonstrates a simple and efficient method for fabricating multiphase heterojunction catalysts, providing new strategies for photothermal CO 2 reduction. [Display omitted] • Plasma-driven metal nanoparticle exsolution. • CeO 2 increases oxygen vacancies. • The localized surface plasmon resonance effect exhibited by Cu. • Excellent reverse water gas shift catalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ni-Co alloy nanoparticles were induced to grow on layered perovskite. • The cell renders 1.53A cm−2 at 2.0 V and 850 °C for CO 2 electrolysis. • Faradic efficiencies of the SOEC are higher than 90 % above 1.6 V. • No degradation was observed in a stability test for 32 h. It has never been more important to develop new technologies that can reduce CO 2 emissions or convert them into useful chemical products. As solid-state electrochemical devices, solid oxide electrolysis cell (SOEC) is capable of converting CO 2 efficiently and selectively into CO or, when combined with water electrolysis, producing syngas (CO and H 2). Herein, we demonstrate a novel layered perovskite oxide, reduced (La 4 Sr 4) 0.9 Ti 7.2 Ni 0.4 Co 0.4 O 26 (LSTNC-r), decorated by exsolved Ni-Co alloy nanoparticles for high-efficiency CO 2 electrolysis. The cell renders a higher activity for electrolysis of CO 2 with a current density of 1.53 A cm−2 @2.0 V and 850 °C. Faradic efficiency measurement and stability test suggest that LSTNC-r are promising fuel electrodes for high-efficient CO 2 electrolysis. [ABSTRACT FROM AUTHOR]

Metal-semiconductor heterostructured catalysts have attracted great attention because of their unique interfacial characteristics and superior catalytic performance. Exsolution of nanoparticles is one of the effective and simple ways for in-situ growth of metal nanoparticles embedded in oxide surfaces and their favorable dispersion and stability. However, both high-temperature and a reducing atmosphere are required simultaneously in conventional exsolution, which is time-consuming and costly, and particles often agglomerate during the process. In this work, Ca 0.9 Ti 0.8 Ni 0.1 Fe 0.1 O 3-δ (CTNF) is exposed to dielectric blocking discharge (DBD) plasma at room temperature to fabricate alloying FeNi 3 nanoparticles from CTNF perovskite. FeNi 3 -CTNF has outstanding catalytic activity for photothermal reverse water gas shift reaction (RWGS). At 350 °C under full-spectrum irradiation, the carbon monoxide (CO) yield of FeNi 3 -CTNF (10.78 mmol g -1 h -1 ) is 11 times that of pure CaTiO 3 (CTO), and the CO selectivity is 98.9%. This superior catalytic activity is attributed to the narrow band gap, photogenerated electron migration to alloy particles, and abundant surface oxygen vacancies. The carbene pathway reaction is also investigated through in-situ Raman spectroscopy. The present work presents a straightforward method for the exsolution of nanoalloys in metal-semiconductor heterostructures for photothermal CO 2 reduction., (© 2023 Wiley‐VCH GmbH.)