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Cathode materials play a crucial role in enabling the widespread adoption of intermediate-temperature solid oxide fuel cells (IT-SOFC) for commercial applications. This study utilized the sol-gel method to prepare a range of perovskite oxides, specifically Sc-doped La 2 Ni 1-x Sc x O 4+δ (x = 0, 0.05, 0.10, and 0.15), without the use of cobalt. The investigation focused on making a study of how the introduction of Sc doping affected the thermal stability, electrochemical properties, and structure of cathode materials. XRD, FE-SEM, and electrochemical workstations were subjected to structural characterization and performance testing of materials. The findings indicate that all the prepared materials have a typical Ruddlesden-Popper structure, and an abundance of additional oxygen can be generated in close proximity to the interstitial by incorporating Sc into the cathode of La 2 Ni 1-x Sc x O 4+δ to increase the oxygen vacancy and improve the catalytic activity of ORR. La 2 Ni 0.9 Sc 0.1 O 4+δ has the highest oxygen surface exchange kinetics, the dissociative adsorption of oxygen is the rate-limiting step at the cathode. At a temperature of 700 °C, the lowest polarization resistance of La 2 Ni 0.9 Sc 0.1 O 4+δ is 0.1298 Ω cm2, while the single cell with La 2 Ni 0.9 Sc 0.1 O 4+δ as the cathode achieves an impressive peak power density of 0.462 W cm−2, thus demonstrating exceptional long-term stability. La 2 Ni 0.9 Sc 0.1 O 4+δ is expected to be a potential high-performance IT-SOFC cathode material. • B‐Site Sc‐doped of cobalt-free La 2 Ni 1-x Sc x O 4+δ cathodes. • Sc-doped creates plentiful oxygen vacancies and increasing oxygen permeability. • Sc-doped improves the ORR activity of La 2 Ni 1-x Sc x O 4+δ cathode. • The TEC of La 2 Ni 0.9 Sc 0.1 O 4+δ cathode is close to conventional electrolyte GDC. • ThePPD of La 2 Ni 0.9 Sc 0.1 O 4+δ cathode at 700 °C is 0.462 W cm−2. [ABSTRACT FROM AUTHOR]

The solid oxide fuel cell (SOFC) is considered promising technology that directly converts the chemical energy stored in the fuel into electrical energy. However, the undesired oxygen reduction reaction (ORR) activity and stability of the cathode have hindered its commercialization. In this work, a series of Pr-doped Pr x Ba 1-x Fe 0.8 Co 0.2 O 3-δ (x = 0∼0.3) nanofibers and powder cathode materials with excellent performance are synthesized by electrospinning and sol-gel methods, respectively. The influence of different Pr doping amounts on the nanofiber morphology, phase structure, thermal stability and electrochemical properties of BaFe 0.8 Co 0.2 O 3-δ (BFCO) nanofibers cathode materials were investigated. Compared the microstructures and electrochemical performance of Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber and powders prepared by different methods. The partial substitution of Pr for Ba (doping of a few of Pr) can effectively eliminate the BFCO hexagonal phase and induce the transformation to the cubic phase. The content of oxygen vacancies was significantly increased as well as the cathode ORR activity was well enhanced. In addition, we demonstrated by DRT that oxygen adsorption is the rate-limiting step at the cathode. Among them, Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber has the best electrochemical performance and the highest oxygen surface exchange kinetics performance. The area-specific resistance (ASR) of Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber is 0.1416 Ω cm2 at 700 °C. When the peak power density (PPD) of the YSZ-NiO/YSZ/GDC/PBCF1–F single cell shows 0.787 W cm−2, an anode-supported fuel cell with Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber demonstrates excellent stability after 100 h of long-term stability test. Electrospinning technology is an effective method to prepare high-performance cathodes, and Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber cathodes are expected to be high-performance cathode materials for IT-SOFCs. • Pr3+ and Co co-doped of BaFeO 3-δ (BFO). • Pr3+ and Co co-doped improves BaFeO 3-δ ORR activity and electrical properties. • DRT analysis of the cathodic oxygen reduction reaction process. • Pr 0.1 Ba 0.9 Fe 0.8 Co 0.2 O 3-δ nanofiber as high-performance solid oxide fuel cathode. [ABSTRACT FROM AUTHOR]

The commercialization of the Co-free solid oxide fuel cell (SOFC) cathode was hindered due to its insufficient oxygen reduction reaction (ORR) activity. In this paper, the ORR activity of the cathode material is effectively increased by doping a small amount of low-valence Ln3+ (Nd3+, Sm3+) ions at the B-site of Fe-based perovskite Bi 0.5 Sr 0.5 FeO 3-δ (BSF). Nd3+ increases the free volume (V free) per unit cell of perovskite due to its larger ionic radius, thus increasing the oxygen vacancy concentration of Bi 0.5 Sr 0.5 Fe 0.95 Nd 0.05 O 3-δ (BSFN). Compared with BSF, BSFN has greatly improved the surface oxygen exchange and volume diffusion rate through the electronic conductivity relaxation (ECR) method. At 700 °C, the area-specific resistance (ASR) of BSFN reached 0.062 Ω cm2, which was 65% lower than that of BSF (0.177 Ω cm2), and the peak power density (PDD) of BSFN-based single cell reached 1.10 W cm−2, which was 1.7 times higher than that of BSF-based single cell (0.64 W cm−2). Through DRT analysis, it is concluded that BSFN can accelerate the adsorption/dissociation process of oxygen due to its higher oxygen vacancy concentration compared with BSF, so that ORR is not limited to the three-phase interface but extends to the entire cathode surface. In addition, in the 80 h long-term stability test at 600 °C, the BSFN-based single cell has better long-term stability because the thermal expansion coefficient of BSFN (14.1 × 10−6 K−1) is lower than that of BSF (14.4 × 10−6 K−1). In general, BSFN is expected to become a Co-free base high-performance intermediate temperature SOFC cathode. [ABSTRACT FROM AUTHOR]

As a potential cathode material for solid oxide fuel cells, the commercial application of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) has to face the challenges in insufficient oxygen reduction reaction (ORR) activity, segregation of Sr element, and CO 2 poisoning. Therefore, the effect of A-site non-stoichiometry on the electrochemical performance of (LS) 1-x CFs (x = −0.05, 0, 0.05, 0.10, 0.15) from the aspect of microstructure/elemental surface chemical environment evolution is investigated in this paper. The results show that (LS) 0.90 CF has the best ORR activity and the highest electrochemical performance. The excellent electrochemical performance is attributed to the (LS) 0.90 CF/Co 2 FeO 4 /CoFe 2 O 4 -type heterostructure, formed by in-situ segregation induced by A-site defects, which improves the surface oxygen diffusion coefficient and chemical bulk diffusion coefficient of the cathode. At the same time, the A-site defect can effectively inhibit the segregation of Sr element in (LS) 0.90 CF, thereby improving the tolerance of CO 2. At 800 °C, the area-specific resistance (ASR) of (LS) 0.90 CF (0.023 Ω cm2) is 66.7% lower than that of LSCF (0.069 Ω cm2), and the peak power density (1.57 Wcm−2) is 1.8 times higher than that of LSCF (0.87 Wcm−2). Therefore, perovskite A-site defect-induced B-site segregation to form heterostructures provides an effective strategy for the preparation of high-performance cathode materials. [ABSTRACT FROM AUTHOR]

Here, in situ assembly in La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ and CoFe 2 O 4 composite (LSCFC) cathode was induced by Pr to form La 0.6 Sr 0.4 Co x Fe y O 3-δ /PrCoO 3 /Co 3 O 4 /PrO 2 (LSCFC-PI) multiphase heterostructures. The surface of LSCFC-PI forms uniform nanoparticles, and the unique core-shell structure prevents Sr segregation, thereby enhancing CO 2 tolerance and increasing oxygen reduction reaction (ORR) active sites. Furthermore, compared with LSCFC, LSCFC-PI increases the oxygen vacancy content of the cathode due to the existence of multiphase heterostructure, improves the ORR kinetics, and the conductivity is also greatly improved. The peak power density (PPD) of LSCFC-PI as a single-cell cathode at 700 ℃ reached 1.51 W cm−2, which was 2.65 times higher than that of LSCFC's 0.57 W cm−2, and in the long-term stability test at a constant voltage ∼0.8 V for 100 hours, showing excellent stability. In situ assembly of multiphase heterostructures is expected to become a new strategy for developing high-performance IT-SOFC cathodes. [Display omitted] • Pr-induced in situ assembly of multiphase heterostructures. • Multiphase heterostructures facilitate the ORR kinetics of cathodes. • Optimize the oxygen vacancy content in multiphase structures. • LSCFC-PI has excellent ORR activity and CO 2 tolerance. [ABSTRACT FROM AUTHOR]

• A negative expansion component SZM is used to balance the thermal expansion. • SNC/SZM heterogeneous interface is constructed by self-assembly. • Heterogeneous interface improves SNC-20SZM ORR kinetics. • The combined SZM increases the TPB length and the O2– transport pathways. • SNC-20SZM exhibits an impressive Rp value of 0.012 Ω cm2 at 700 °C. The discrepancy in thermal expansion coefficients (TECs) between the cobalt-based cathode and the electrolyte presents a notable obstacle in attaining optimal performance levels for solid oxide fuel cells (SOFCs). Here we propose to introduce negative thermal expansion (NTE) component Sm 0.85 Zn 0.15 MnO 3 (SZM) to SrNb 0.1 Co 0.9 O 3−δ (SNC) cathode to prepare SNC-xSZM (x = 0, 10, 20 and 30 %) composite cathode materials. The impact of incorporating negative thermal expansion material on the composition and properties of the matrix materials were examined by X-ray diffraction, thermal dilatometer, high-resolution transmission electron microscopy, and electrochemical workstation. The results show that SNC-xSZM can achieve more ideal thermal matching with Ce 0.8 Gd 0.2 O 1.9 (GDC), and the thermal expansion coefficient decreases observably from 25.47 × 10−6 K−1 for x = 0 to 13.74 × 10−6 K−1 for x = 30 %. The optimal comprehensive electrochemical performance is obtained for SNC-20SZM, which possesses the minimum polarization resistance (Rp) of 0.012 Ω cm2 at 700 °C. The SNC-20SZM-based cell shows a maximum peak power density (PPD) of 1.22 W cm−2 while exhibiting stable operation for a continuous duration of 120 h at a constant current of 0.8 A cm−2, with performance remaining optimal. Moreover, SNC-20SZM demonstrates exceptional durability and stability over prolonged durations even in high CO 2 atmospheres. An innovative approach for enhancing the development of intermediate-temperature solid oxide fuel cells (IT-SOFCs) involves incorporating SZM in the SNC cathode, thereby augmenting electrochemical performance and narrowing the gap in the thermal expansion coefficient among SOFC modules. [ABSTRACT FROM AUTHOR]

The development of cathode materials with high oxygen reduction reaction (ORR) activity and stability in intermediate temperature (IT) environments is a key factor in the commercialization of solid oxide fuel cells (SOFC). In this paper, the ORR activity of the cathode is improved by doping high-valent Sc3+ ions at the B-site of the Sr 0.5 La 0.5 Co 0.8 Cu 0.2-x Sc x O 3–δ (x = 0, 0.02, 0.04), in which Sr 0.5 La 0.5 Co 0.8 Cu 0.18 Sc 0.02 O 3–δ (SLCCS2) shows the best electrochemical performance, and the area-specific resistance of SLCCS2 at 700 °C is only 0.047 Ω cm2, much lower than the 0.087 Ω cm2 of Sr 0.5 La 0.5 Co 0.8 Cu 0.2 O 3–δ (SLCC), and the peak power density of SLCCS2 reached 1.098 W cm−2, which is 1.84 times that of SLCC (0.598 W cm−2). In addition, SLCCS2 effectively reduces the thermal expansion coefficient, improves thermal matching with traditional electrolytes, and overcomes the problem of insufficient long-term SOFC stability caused by the high thermal expansion coefficient of Co-based perovskite to a certain extent. SLCCS2 also exhibits excellent CO 2 tolerance. Considering comprehensively, SLCCS2 is expected to become an IT-SOFC cathode material with development potential. • Sc doping improves the ORR activity of Sr 0.5 La 0.5 Co 0.8 Cu 0.2 O 3–δ. • Sc doping reduces thermal expansion coefficient of Co-based perovskites. • Sr 0.5 La 0.5 Co 0.8 Cu 0.18 Sc 0.02 O 3–δ has excellent CO 2 tolerance. [ABSTRACT FROM AUTHOR]

The effect of a small addition of MoO3 on the microstructure and ionic conductivity of Nd0.2Ce0.8O1.9 (NDC), La0.8Sr0.2Ga0.8Mg0.2O2.8 (LSGM) and Nd0.2Ce0.8O1.9-La0.8Sr0.2Ga0.8Mg0.2O2.8 (NDC-LSGM) has been investigated. The microstructure and electrical properties of the samples were characterized by X-ray diffraction, field-emission scanning electron microscopy and electrochemical impedance spectroscopy. The results show that MoO3 doping can obviously increase the densification and grain sizes, and decrease the grain and grain boundary resistances of the NDC, LSGM and NDC-LSGM electrolytes. It expands the oxygen ion channels and reduces the total conductance activation energy of the system. The total conductivities of MoO3-doped NDC and NDC-LSGM samples are 1.56 and 2.10 times higher than that of the undoped NDC system at 450°C. The total conductivity of LSGM-Mo is 1.46 times higher than that of LSGM at 450°C. These finding suggest that MoO3 is considered to be an effective sintering aid that optimizes the electrical properties of NDC, LSGM and NDC-LSGM electrolytes. [ABSTRACT FROM AUTHOR]

The geometrical structures and phosphorescence efficiency of two series of iridium(iii) complexes with wide-range color tuning have been focused on in this work. A DFT/TDDFT (density functional theory/time-dependent density functional theory) investigation on the electronic structure in the ground and lowest triplet excited states, the frontier molecular orbitals, the absorption spectra, and phosphorescence properties of 1–1d and 2–2d has been performed to get a better understanding of the relationship between the structure and property. Importantly, the nature of the N-substituents can influence the electron density distributions of frontier molecular orbitals and their energies, resulting in a change in transition character and emission color, while the attached –CF3 or –C(CH3)3 group on the triazole moiety has an impact on the radiative decay constants of all the complexes. The higher quantum yields of 1a, 1c, 2a, and 2c compared to 1b, 1d, 2b, and 2d can be explained by their larger separation between 3MLCT/π→π* and 3MC d–d states, and the designed 1a and 2a with high quantum efficiency are considered to be potential candidates for deep blue and blue-emitting materials, respectively. [ABSTRACT FROM AUTHOR]

As a Ruddlesden-Popper (RP) phase solid oxide fuel cell (SOFC) cathode material, Pr 2 NiO 4+δ (PNO) is a critical challenge for SOFC commercialization due to the lack of oxygen vacancies and insufficient redox reaction (ORR) activity. In this paper, various concentrations of La 0.6 Sr 0.4 CoO 3-δ (LSC) nanoparticles are coated on the surface of PNO by an impregnation method, and the ORR kinetics of PNO is found to be improved by constructing a composite cathode with heterointerfaces. The formation of the heterointerface effectively enhances the transfer of interstitial oxygen in the PNO and the oxygen vacancies in LSC, which can promote the conduction of O2− in the cathode and thus improves the ORR activity of the material. When the impregnation concentration of LSC reached C LSC = 0.2 mol L−1, the ORR activity can reach the highest level. At 700 °C, the area-specific resistance of PNO-LSC reaches 0.024 Ω cm2, which is 83.4% lower than that of PNO (0.145 Ω cm2). And the peak power density of PNO-LSC reaches 0.618 W cm−2, which is 1.89 times larger than that of PNO (0.327 W cm−2). Therefore, the construction of composite cathodes with heterointerfaces via impregnation provides an alternative strategy for enhancing the ORR activity of the cathode materials in SOFC. [Display omitted] • Pr 2 NiO 4+δ -La 0.6 Sr 0.4 COO 3-δ cathode is prepared by impregnation method. • The heterointerface promotes the ORR activity of the cathode. • Pr 2 NiO 4+δ -La 0.6 Sr 0.4 COO 3-δ has excellent ORR activity. [ABSTRACT FROM AUTHOR]

Abstract: The effects of MoO3 concentration on the sintering and electrical properties of Ce0.8Nd0.2O1.9 + 500 ppm SiO2 (NDCSi) and (Ce0.8Nd0.2O1.9)1 − x (MoO3) x  + 500 ppm SiO2 ( x = 0.01, 0.02, 0.03, 0.04, 0.05, NDCSi + 1MoO3, NDCSi + 2MoO3, NDCSi + 3MoO3, NDCSi + 4MoO3, NDCSi + 5MoO3) prepared through a modified sol–gel method were systematically investigated. The structures and ionic conductivities were characterized by XRD, FE-SEM and EIS. The results indicated a sharp increase in densification and conductivity for the system of NDCSi containing small amount of MoO3. It shows that NDCSi + 3MoO3 exhibited much higher relative density (RD = 96%), higher conductivity (σ t = 1.25 × 10−2 S cm−1 at 600 °C) and lower activation energy (E a = 0.81 eV) compared with NDCSi and the other MoO3 doped-NDCSi samples. Furthermore, MoO3 could be used as an effective sintering aid and a grain boundary scavenger for NDCSi system. And we obtained the optimal amount of the MoO3 is 3 mol%. [Copyright &y& Elsevier]

We report on a successful fabrication of three-dimensional architectures of nanostructural WO 3 assembled by building blocks comprising nanoparticles, nanorods, and nanoplates by hydrothermal method. We find that the additives of oxalic acid and urea and their relative molar ratio are critical to forming 3D WO 3 architectures and that the sample prepared with the H 2 C 2 O 4 /H 2 NCONH 2 molar ratio of 0.02/0.005 show a much more regular shape with sphere-like feature than that prepared with the molar ratio of 0.01/0.05, which consequently gives rise to more intense UV emission around 305 nm. Such effective control of 3D WO 3 architectures by manipulating the types of additives and their relative molar ratio is applicable to the fabrication of other unique 3D nanostructures with preferable luminescence properties. [ABSTRACT FROM AUTHOR]

• Ni-doped Fe-based perovskite enhances ORR activity. • Ni doping reduces the energy barrier of surface oxygen diffusion and bulk diffusion. • LSCFN15 is expected to be an electrode with dual functions of ORR and OER.. • The ORR rate-limiting steps of Ni-doped electrodes were analyzed through DRT. This paper systematically studies Ni doping at Fe sites in La 0.6 Sr 0.4 Co 0.3 Fe 0.7 O 3-δ (LSCF) as an intermediate temperature solid oxide fuel cell (IT-SOFC) electrode. The electrocatalytic activity of Ni-doped electrodes in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) modes was analyzed, rather than individual cathode or anode. The results indicate that Ni doping increases the internal vacancies, ORR activity, and charge transfer ability of La 0.6 Sr 0.4 Co 0.3 Fe 0.6 Ni 0.15 O 3-δ (LSCFN15). In addition, compared to LSCF, LSCFN15 also reduces the energy barriers for surface oxygen exchange and bulk diffusion, thereby increasing the overall ORR kinetic rate. Combined with the distribution of relaxation time (DRT) analysis, it was confirmed that Ni-doped LSCFN15 increased the adsorption and dissociation rates of oxygen. At 750 ℃, the area-specific resistance (ASR) of LSCFN15 reached 0.045 Ω cm2, which is only 58.4 % of LSCF (0.077 Ω cm2). As a SOFC cathode, the peak power density (PPD) reached 1175 mW cm−2, 1.31 times that of LSCF (898 mW cm−2). As a SOFC anode, the current exchange density of LSCFN15 in OER mode reaches 164 mA cm−2, which is higher than the 125 mA cm−2 of LSCF, indicating that LSCFN15 also has the potential to serve as an anode for SOFC. In addition, Ni doping reduces the thermal expansion coefficient of the electrode and improves its thermal compatibility with traditional electrolytes. As an electrode, LSCFN15 exhibits excellent long-term stability in both SOFC and SOEC modes. Overall, Ni-doped Fe-based perovskite can improve the ORR and OER activities while enhancing the stability of cell operation and is expected to obtain multifunctional SOFC electrode materials. [ABSTRACT FROM AUTHOR]

Many feature extraction components have been proposed for image deraining tasks, aiming to improve feature learning. However, few models have addressed the integration of multi-scale features from derain images. The fusion of multiple features at different scales in one model has the potential to significantly enhance the authenticity and detail of rainy images restoration. This study introduces a migratable multi-scale feature blending model, which is a progressive learning model based on detail dilation and texture extraction. First, the degraded image is sent to the detail dilation module, which is designed to increase the detailed outline and obtain the coarse image features. Second, the extracted feature maps are sent to the multi-scale feature extraction (MFE) module and the multi-scale hybrid strategy (MHS) module for improved texture restoration. Third, the simple convolution modules are replaced by an optimized transformer model to more efficiently extract contextual features and multi-scale information in images. Finally, a progressive learning strategy is employed to incrementally restore the degraded images. Empirical results show that our proposed module for progressive restoration achieves near state-of-the-art performance in several rain removal tasks. In particular, our model exhibits better rain removal realism compared to state-of-the-art models. The source code is available at https://github.com/JackAILab/DTPNet. • Introduce detail scaling module to extract generalized features from rainfall image. • Improved Transform block was introduced to enhance the model's generalized ability. • Scale-mixing strategy is proposed for capturing more multi-scale features in images. [ABSTRACT FROM AUTHOR]

The cobalt-free cathode materials with high activity is critical to the commercial application of medium temperature solid oxide fuel cells (IT-SOFC). Herein, a series of cobalt-free Nb-doped Pr 2 Ni 1- x Nb x O 4 (x = 0, 0.05, 0.10, and 0.15) perovskite oxides were successfully prepared, and the effects of Nb-doping on the structure, thermal stability and electrochemical properties of the cathode material are studied in detail. The Pr 2 Ni 1- x Nb x O 4 exhibits a K 2 NiF 4 type structure with Fmmm space group. The Nb5+ cations that doped into Pr 2 NiO 4 replaces the Ni site, which increases the surface oxygen content, then effectively eliminates the phase transition of Pr 2 NiO 4 and significantly improves the ORR catalytic activity. The Pr 2 Ni 0.9 Nb 0.1 O 4 was found to occupy the lowest polarization resistance of 0.057 Ω cm2, and the peak power density of single cells supported by the electrolyte is 0.576 W cm−2 at 700 °C, which has good long-term stability. [Display omitted] • The structure and performance of the cobalt-free Pr 2 Ni 1- x Nb x O 4 cathodes are studied. • Nb-doping can eliminate the phase change and improve the stability of the structures. • Nb-doping can increase the ORR activity of the Pr 2 Ni 1- x Nb x O 4 cathode. • Pr 2 Ni 0.9 Nb 0.1 O 4 cathode exhibits a low polarization resistance of 0.057 Ω cm2. • The highest peak power density is 0.576 W cm−2 at 700 °C with Pr 2 Ni 0.9 Nb 0.1 O 4 cathode. [ABSTRACT FROM AUTHOR]

The electrospinning and sol-gel methods are used to prepare a Ba 0·5 Sr 0·5 Fe 0·8 Cu 0·2 O 3-δ (BSFC) cathode material with good chemical compatibility with the traditional electrolyte Ce 0.8 Gd 0.2 O 2−δ (GDC). Systematic experiments are performed to investigate the effect of sintering temperature on BSFC fibers microstructure, morphology and electrochemical properties. The results show that the three dimensional (3D) BSFC-F800 prepared by the low-temperature calcination method (800 °C) has a well-organized porous structure and larger specific surface area and porosity. In addition, the fibers are connected to each other to form a continuous electrode path, which provides an uninterrupted channel for charge transmission, and the low-temperature calcination can efficiently reduce the surface Sr segregation and increase ORR activity. At 700 °C, the 3D nanofiber cathode material BSFC-F800 has lower area specific resistance (ASR = 0.128 Ω cm2) and higher peak power density (PPD = 0.51 W cm−2). The voltage decay rate in the 100 h long-term stability test is only 0.0342% h−1. Changes of morphology and electrical properties of Ba 0·5 Sr 0·5 Fe 0·8 Cu 0·2 O 3-δ fibers prepared by electrostatic spinning at different calcination temperatures. After calcination at low temperature, a hollow 3D fiber cathode with higher specific surface area is obtained. With the increase of temperature, grain expands, fiber diameter increases, and hollow structure becomes solid structure. As the temperature continues to rise, the fibers agglomerate together, seriously damaging the specific surface area and porosity of Ba 0·5 Sr 0·5 Fe 0·8 Cu 0·2 O 3-δ fibers. Image 1 • B-site Cu doped Fe-based Ba 0·5 Sr 0·5 Fe 0·8 Cu 0·2 O 3-δ fiber cathode material. • 3D structure fiber was prepared by low temperature method. • Low temperature sintering can effectively reduce the surface Sr segregation. • 3D structure Ba 0·5 Sr 0·5 Fe 0·8 Cu 0·2 O 3-δ has excellent performance. [ABSTRACT FROM AUTHOR]

Nd 0.2 Ce 0.8 O 3-δ (NDC) is one of the most common solid electrolyte materials used in solid oxide fuel cells (SOFCs). However, the densification temperature of NDC electrolyte is above 1400 °C. In this work, Bi 2 O 3 and CoO sintering aids were individually or synergistically added to Nd 0.2 Ce 0.8 O 3-δ (NDC) electrolytes through the sol-gel method to lower its sintering temperature. Effects of Bi 2 O 3 -CoO dual sintering aid on the sintering behavior, phase composition, microstructure, and electrochemical properties of NDC electrolyte were all investigated. The data revealed that Bi 2 O 3 -CoO dual-sintering aid doped-NDC (labeled as NDC-CB) possessed high density and superior conductivity at low temperatures, better than that of Bi 2 O 3 or CoO single sintering aid. NDC electrolyte doped with Bi 2 O 3 -CoO dual-sintering aid achieved highest relative density of 95.3% at 1100 °C and total conductivity of 5.765 × 10-2 S cm-1 at 800 °C. Furthermore, NDC-CB displayed excellent physical and chemical compatibility with La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ (LSCF) cathode and NiO-NDC anode. Oxygen reduction reaction at LSCF/NDC-CB interface was improved by about 40% when compared to NDC. In sum, Bi 2 O 3 -CoO looks promising as dual-sintering additive for lowing sintering temperature and increasing electrical conductivity of NDC. Therefore, NDC-CB might be potential electrolyte for future intermediate-temperature solid oxide fuel cells (IT-SOFCs). • The density and properties of NDC samples with sintering aids were improved. • NDC with Bi 2 O 3 -CoO dual-sintering aid exhibited the excellent performance. • Dual-sintering aid enhancement was superior to single sintering aids. • NDC co-doped with Bi 2 O 3 -CoO achieved the highest relative density of 95.3%. • The total conductivity of NDC-CB was 5.765 × 10-2 S cm-1 at 800 °C. • 1–24. [ABSTRACT FROM AUTHOR]

We demonstrate the utilization of bismuth tungstate (Bi 2 WO 6 , BW) as a sintering aid and reinforcement component into neodymium-doped ceria (Nd 0.2 Ce 0.8 O 3-δ , NDC) to fabricate bismuth tungstate/neodymium-doped ceria composite electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFC). The presence of BW lowers the sintering temperature of NDC electrolyte to 1000 °C. Moreover, at 600 °C, the electrical conductivity of 5 mol.% BW-incorporated NDC (5BW-NDC) composite electrolyte is 7.12 times higher than the NDC. It is worth mentioning that the enhanced electrical conductivity of 5BW-NDC composite electrolyte does not include the contribution from electronic conductivity. Furthermore, NDC and 5BW-NDC exhibit excellent compatibility with La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ cathode and NiO anode in terms of thermal expansion coefficient and chemical reactivity. The oxygen reduction reaction at 5BW-NDC composite electrolyte/cathode interface is significantly enhanced by ∼40% compared to NDC. Moreover, 5BW-NDC electrolyte-supported SOFC delivers a power density of 0.86 W cm−2 at 700 °C, which is 45.76% higher than the NDC-based SOFC. The output performance remains stable during high-temperature operation for 120 h, which indicates the stability and chemical compatibility of the as-synthesized composite electrolyte with other cell components. The results reveal that BW-NDC composite is a potential electrolyte material for stable and high-performance IT-SOFCs. • A novel BW-NDC composite ceramics is developed to act as electrolyte of SOFCs. • BW-NDC ceramics is densified at 1000 °C due to BW played the role of sintering aid. • BW-NDC exhibits 7.27 times higher ionic conductivity than that of NDC. • ∼40% improvement of oxygen reduction reaction and power density with BW-NDC ceramics. [ABSTRACT FROM AUTHOR]

A series of Nd/Mg co-doped ceria electrolytes, Ce0.8Nd0.2−xMgxO2−δ(x = 0, 0.05, 0.10 and 0.15), were synthesised through a facile solgel method. The structure and electrical properties were characterised by X-ray diffraction, scanning electron microscopy and AC impedance spectroscopy. An appropriate elemental ratio of Nd/Mg in the co-doped experiment was found to be essential in improving the electrical performance of the ceria-based electrolytes. The optimum grain-boundary conductivity (2.28 × 10−2 S cm−1) and total conductivity (2.68 × 10−3 S cm−1) were obtained at the doping 10 at.% Nd and 10 at.% Mg. [ABSTRACT FROM AUTHOR]

Two series of platinum(II) complexes with triarylboron/triarylnitrogen-functionalized N-heterocyclic carbene chelate ligands have been theoretically investigated by using the density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The influence of different substituents (triarylboron-functionalized or triarylnitrogen-functionalized) on the electronic structure and optical properties of Pt(II) complexes was also explored. The results reveal that the different substituents can influence the electron density distributions of frontier molecular orbitals and their energies, resulting in the change of transition character and emission color. The designed complex 1b and 1d are considered to be a potential candidate as deep blue-emitting material. [ABSTRACT FROM AUTHOR]

Based on the complexes [Ir(dfb-pz)2(tfmtyp)] (1) and [Ir(tfmfb-pz)2(tfmtyp)] (2) [dfb-pz = 2,4-difluorobenzyl-N-pyrazole; tfmtyp = 2-(5-trifluoromethyl-[1,2,4]triazol-3-yl)-pyridine; tfmfb-pz = 2-tri-fluoromethyl-5-fluorobenzyl-N-pyrazole], two series of Ir(iii) complexes have been designed by substituting “CH” groups with the N atom at -a, -b, -c, and -d positions on the pyridine moiety in N^N ligands. The electronic structure, absorption and emission spectra as well as phosphorescence efficiency of all these Ir(iii) complexes were investigated by using density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The calculated results show that the assumed complexes 1a and 2a may possess a higher photoluminescent quantum efficiency than other complexes and are potential candidates as efficient blue-emitting materials. This study shows that the N substitution can tune the emission color of 1 and 2 and enhance the photoluminescence quantum efficiency. [ABSTRACT FROM AUTHOR]

Self-assembly of zinc(II) coordination polymers have attracted intense interests due to their intriguing frameworks and fluorescence properties. Two new 3D ZnII coordination polymers with pcu networks, formulated by [Zn2L1L2(mbtz)] ·H2O ( 1) and [Zn4L12L22(btp)2] ·7H2O ( 2) [H2L1 = 2,5-dibenzoylterephthalic acid, H2L2 = 4,6-dibenzoylisophthalic acid, mbtz = 1,3-bis(1,2,4-triazol-1-ylmethyl)benzene, and btp = 1,3-bis(1,2,4-triazol-1-yl)propane], were synthesized under normal hydrothermal conditions. Single-crystal X-ray diffraction analyses revealed that both of the two compounds exhibited interesting 3D pcu frameworks, and showed shifted fluorescent emissions arising from the coordination chemistry between ZnII and the N-donor ligands. [ABSTRACT FROM AUTHOR]

A glassy carbon electrode (GCE) was covalently modified by 4-phosphatephenyl (4-PP). Sensing paracetamol (PCT) via linear sweep voltammetry in sulfuric buffer solution of pH 1.02 at 36.8 °C, the 4-PP-modified GCE showed high electrochemical sensitivity and long reusability. PCT-loaded poly(vinyl alcohol) (PVA) nanofibers were prepared by electrospinning. Based on the calibration curve of PCT on the 4-PP-modified GCE, the PCT release process from the nanofibers was electrochemically monitored in real time via two routes. The results showed that the covalently modified GCE can be repeatedly used as real-time electrochemical monitoring platform for drug release from drug-loaded nanofibers in the long term. [ABSTRACT FROM AUTHOR]

Different organic molecules were covalently grafted on glassy carbon electrodes (GCEs) by an electrochemical reduction or potentiostatic process of several in situ-generated diazonium cations in acidic aqueous solution containing NaNO. The cyclic voltammetry implemented in 0.1 M KCl aqueous solution containing 5 mM Fe(CN) or Ru(NH) confirmed the blocking properties of the modified GCEs. The electrochemical impedance spectroscopy (EIS) performed in 0.1 M KCl aqueous solution containing 5 mM Fe(CN) was used to measure the surface coverage of the modifiers on GCE; the results showed that the modified layers on GCEs are very compact. The linear sweep voltammetry (LSV) was employed to investigate the electrochemical sensing properties of the bare and modified GCEs toward paracetamol (PCT) in sulfuric acid solution of pH 1.02, and the corresponding calibration plots were obtained, respectively. The results indicated there is an oxidation peak of PCT in the linear sweep voltammograms on the bare and modified GCEs with the active terminal groups such as −OPOH, −SOH, −COOH, and so on, but do not appear on GCEs modified with the inert terminal groups such as −NO and −Br. These imply that the GCEs modified with the active terminal groups display an electrochemical behavior like bulk GCE; however, those with the inert terminal groups present an electrochemical behavior like microelectrode. The varying electrochemical sensitivity of all the electrodes toward PCT was explained according to electronegativity and p K of the terminal groups of the modifiers on the electrodes and hydrogen bond between the modifiers and PCT. Apparent standard rate constants of PCT oxidation reaction on the bare and modified GCEs were obtained from the Laviron's approach. [ABSTRACT FROM AUTHOR]

Abstract: Palladium nanoparticles (PdNPs) modified indium tin oxide (ITO) electrode was fabricated via electrospinning followed by calcination. The results of scanning electron microscopy (SEM) images and X-ray photoelectron spectroscopy (XPS) indicated the PdNPs were immobilized on the ITO electrode surface successfully. The electrochemical behavior of the modified electrodes could be adjusted easily by changing the collected time of electrospinning. The prepared electrodes exhibited high sensitivity, good reproducibility and stability toward NO2 −. The current responses were linear with NO2 − concentrations in a wide range with low detection limit. The proposed method can be successfully applied to the determination of NO2 − in real water samples. [Copyright &y& Elsevier]

In order to optimize the electrical properties of co-doped ceria electrolytes, Ce 0.8 Ca 0.15 Sm 0.05 O 2− δ (CCS) sintered at different temperatures (1150 °C, 1200 °C, 1250 °C, 1300 °C and 1350 °C for 8 h) have been prepared and systematically investigated. It is found that among these samples sintered at different conditions, the electrical conductivity ( σ ) measured at 800 °C can be ranked as: CCS 1250 °C : σ CCS 1250 ° C 800 ° C = 2.38 × 10 −2 S cm −1 > CCS 1200 °C : σ CCS 1200 ° C 800 ° C = 1.81 × 10 −2 S cm −1 > CCS 1150 °C : σ CCS 1150 ° C 800 ° C = 1.50 × 10 −2 S cm −1 > CCS 1300 °C : σ CCS 1300 ° C 800 ° C = 1.26 × 10 −2 S cm −1 > CCS 1350 °C : σ CCS 1350 ° C 800 ° C = 0.68 × 10 −2 S cm −1 . The electrical conductivity of CCS increases with the increase of sintering temperatures, and the 1250 °C-sintered sample presents the highest conductivity because of the best microstructures. However, the electrical conductivity of CCS decreases when the sintering temperatures goes beyond 1250 °C. We attribute this to the phase instability. It reveals that microstructures and the phase stability have important effects on the optimization of electrical properties for the co-doped ceria electrolytes. [ABSTRACT FROM AUTHOR]

Abstract: In order to optimize the electrical properties of co-doped ceria electrolytes, Ce0.8Ca0.15Sm0.05O2−δ (CCS) sintered at different temperatures (1150 °C, 1200 °C, 1250 °C, 1300 °C and 1350 °C for 8 h) have been prepared and systematically investigated. It is found that among these samples sintered at different conditions, the electrical conductivity (σ) measured at 800 °C can be ranked as: CCS1250 °C:  = 2.38 × 10−2 S cm−1 > CCS1200 °C:  = 1.81 × 10−2 S cm−1 > CCS1150 °C:  = 1.50 × 10−2 S cm−1 > CCS1300 °C:  = 1.26 × 10−2 S cm−1 > CCS1350 °C:  = 0.68 × 10−2 S cm−1. The electrical conductivity of CCS increases with the increase of sintering temperatures, and the 1250 °C-sintered sample presents the highest conductivity because of the best microstructures. However, the electrical conductivity of CCS decreases when the sintering temperatures goes beyond 1250 °C. We attribute this to the phase instability. It reveals that microstructures and the phase stability have important effects on the optimization of electrical properties for the co-doped ceria electrolytes. [Copyright &y& Elsevier]

Abstract: The effect of small addition of different sintering aids (MoO3 and WO3) on the electrical properties of Ce0.9Nd0.1O2−δ has been investigated. The (Ce0.9Nd0.1)1−x M x O2−δ (x = 0.0; M = Mo, W, x = 0.01; Ce0.9Nd0.1O2−δ : NDC, (Ce0.9Nd0.1)0.99Mo0.01O2−δ : NDCMo; (Ce0.9Nd0.1)0.99W0.01O2−δ : NDCW) solid solutions were prepared and characterized. The X-ray diffraction patterns indicate that all the samples are single phases with a cubic fluorite structure. Moreover, from the field-emission scanning electron microscopy results, it is found (Ce0.9Nd0.1)0.99M0.01O2−δ (M = Mo, W) sintered at 1300 °C for 15 h have better sinterability than Ce0.9Nd0.1O2−δ . The total conductivity by electrochemical impedance spectroscopy are ranked as: NDCW  > NDCMo  > NDC measured at 700 °C, which is attributed to microstructures. It can be concluded that MoO3 and WO3 are both effective and WO3 seems to be more potential as sintering aids on the optimization of electrical properties for ceria-based electrolytes. [Copyright &y& Elsevier]

Abstract: In order to identify competitive ion-conducting materials in ceria-carbonates composite electrolytes, M-NLCO (M = Ce0.8Sm0.2O2-δ (SDC), Ce0.8Gd0.2O2-δ (GDC), Ce0.8Y0.2O2-δ (YDC); NLCO = 0.53Li2CO3–0.47Na2CO3) sintered at different temperatures (600° C, 625° C, 650° C, 675° C and 700° C) have been prepared and characterized. It is found that independent of systems, the 675° C-sintered composites in M-NLCO always present the highest conductivities because of the best NLCO distribution and interfacial microstructures. Moreover, among three composites (sintered at 675° C), the total () and grain boundary () conductivities measured at 600° C are ranked as: SDC-NLCO (, ) ﹥ GDC-NLCO (, ) ﹥ YDC-NLCO (, ), which is attributed to ionic-radius compatibility between the dopant and the host as well as the NLCO distribution and interfacial microstructures. It can be concluded that ionic-radius compatibility between the dopant and the host, NLCO distribution and interfacial microstructures have important effects on improving ionic conductivities for ceria-carbonates composite electrolytes. [Copyright &y& Elsevier]

Abstract: The electronic and magnetic properties of Y Ba2Fe3O8 have been systematically investigated within the framework of density-functional theory using the standard generalized gradient approximation (GGA) as well as the GGA plus Hubbard method. The GGA results show that the G-type antiferromagnetic (AFM) state is preferred among the considered magnetic configurations. The striking ionic character is shown for Y and Ba atoms while very strong hybridization is found between Fe 3d and O 2p orbitals. Furthermore, the Fe–O–Fe superexchange interaction should be responsible for the stability of the AFM magnetic structure in this case. In addition, our theoretical calculations reveal that the ground state of Y Ba2Fe3O8 is a strongly correlated charge-transfer insulator with a finite band gap above the Fermi level obtained by the scheme, which is in agreement with the experimental observations. [Copyright &y& Elsevier]

Abstract: The elastic anisotropy of the potential low compressible and hard materials OsB2 and RuB2 were studied by first-principles investigation within density functional theory. The structure, elastic constants, bulk modulus, shear modulus, Poisson''s ratio and Debye temperature have been calculated within both local density approximation (LDA) and generalized gradient approximation (GGA). The results indicated that the calculated bulk modulus and shear modulus were in good agreement with the experimental and previous theoretical studies. The calculated elastic constants anisotropic factors and directional bulk modulus showed that OsB2 and RuB2 possess high elastic anisotropic. [Copyright &y& Elsevier]

A novel Pr 2 NiO 4 (PNO)-Pr 0.2 Ce 0.8 O 1.9 (PCO) composite material was synthesized by typical solid state mixing and modified sol-gel method, and was assessed as a cathode material candidate for intermediate temperature solid oxide fuel cells (IT-SOFCs). The effects of different preparation methods on the microstructure, transport properties, and stability of electrode materials were systematically investigated. It was found that the introduction of PCO enhanced the electrochemical activity of PNO electrode. Among the composite materials, PNO–PCO composite cathode obtained by sol-gel method exhibited the best electrochemical performance. The polarization resistance (R P) on GDC electrolyte was 0.09 Ω cm2 at 800 °C. The NiO-GDC/GDC/PNO–PCO single cell yielded maximum output power of 0.57 W cm−2 at 800 °C. Furthermore, the R P exhibited an excellent stability after polarization for 120 h, indicating the good chemical compatibility of PNO–PCO composite cathode with other cell components. The desirable electrochemical properties and stability of PNO–PCO composite demonstrate its potential as a cathode material for IT-SOFCs. PNO–PCO composite was investigated as a promising cathode material for IT-SOFCs. PNO–PCO composite cathode prepared by sol-gel method exhibited low polarization resistance of 0.09 Ω cm2 at 800 °C, the electrolyte-supported single cell yielded a maximum power density of 0.57 W cm−2 at 800 °C. Image 1 • A novel PNO–PCO composite cathode is developed to act as cathode of SOFCs. • PCO exhibits excellent catalytic activity for cathodic ORR. • Composite prepared by sol-gel method has sufficient active sites for cathode ORR. • 46.2% improvement of power density with SGPP composite cathode. [ABSTRACT FROM AUTHOR]

Thermoplastic polyimide (TPI) was synthesized via a traditional one-step method using 2,3,3′,4′-biphenyltetracarboxylic dianhydride (3,4′-BPDA), 4,4′-oxydianiline (4,4′-ODA), and 2,2′-bis(trifluoromethyl)benzidine (TFMB) as the monomers. A series of semi-interpenetrating polymer networks (semi-IPNs) were produced by dissolving TPI in bisphenol A dicyanate (BADCy), followed by curing at elevated temperatures. The curing reactions of BADCy were accelerated by TPI in the blends, reflected by lower curing temperatures and shorter gelation time determined by differential scanning calorimetry (DSC) and rheological measurements. As evidenced by scanning electron microscopy (SEM) images, phase separation occurred and continuous TPI phases were formed in semi-IPNs with a TPI content of 15% and 20%. The properties of semi-IPNs were systematically investigated according to their glass transition temperatures (Tg), thermo-oxidative stability, and dielectric and mechanical properties. The results revealed that these semi-IPNs possessed improved mechanical and dielectric properties compared with pure polycyanurate. Notably, the impact strength of semi-IPNs was 47%–320% greater than that of polycyanurate. Meanwhile, semi-IPNs maintained comparable or even slightly higher thermal resistance in comparison with polycyanurate. The favorable processability and material properties make TPI/BADCy blends promising matrix resins for high-performance composites and adhesives. [ABSTRACT FROM AUTHOR]