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Abstract: Ceria cubes decorated with manganese oxide nanoparticles (Mn2O3/CeO2 nanocubes) were synthesized and used to modify a Au electrode for analysis of As(III) in aqueous solution. This modified electrode displayed improved sensitivity than either oxide on their own, indicating a synergistic effect due to the effect of Mn2O3 on the properties of CeO2. The improved sensitivity could be ascribed to the enhanced As (III) adsorption ability of Mn2O3/CeO2 nanocube during electrochemical pre‐concentration, combined with the well known As(III) sensing qualities of the gold substrate. The Mn2O3/CeO2 nanocube modified gold electrode behaved as a promising sensor with stable, repeatable square wave anodic stripping voltammetry (SWASV) peaks, separated from common interfering ions in natural water including Cu (II) under practical conditions. Repeatability and stability studies revealed the As (III) sensor to be robust and reliable, with a sensitivity of 0.0414 μA/ppb and a limit of detection (LoD) of 3.35 ppb under optimized conditions, indicating a possible general use of this class of heteronanostructures in electroanalytical chemistry for studies that rely upon adsorption of deposition of the analyte prior to stripping analysis. [ABSTRACT FROM AUTHOR]

Compositionally continuously graded cathode layers (CGCLs) of (Ba0.5Sr0.5)(Fe0.91Al0.09)O3−δ –Gd0.1Ce0.9O2 (BSFA–GDC) have been constructed by a handy and effective technique called wet powder spraying (WPS). CGCLs exhibit similar thermal expansion coefficient (TEC) value between adjacent thin layers. The continuously graded structure and the well-distributed components of BSFA–GDC cathode are confirmed by morphological characterization with scanning electron microscopy (SEM), and by compositional analysis with energy dispersion X-ray spectrometer (EDS), respectively. The polarization resistance (R p) of CGCLs with three different thicknesses is investigated by electrochemical impedance spectra (EIS). The EIS results show that CGCLs with a moderate thickness of 20 μm achieve the lowest R p of 0.301 Ω cm2 at 800 °C. In addition, anode-supported single cells with the configuration of NiO–YSZ/YSZ/GDC/BSFA–GDC have been fabricated and tested. The cell with the CGCLs thickness of 20 μm reaches the highest output power density of 848 mW cm−2 at 800 °C. [ABSTRACT FROM AUTHOR]

Abstract: Herein a chemical reduction method is proposed in order to modify the solid oxide fuel cells (SOFC) traditional cathode material La0.8Sr0.2MnO3−x (LSM). Silver nanoparticles were prepared by the reduction of ammoniacal silver nitrate with ascorbic acid in dilute aqueous solutions containing PVP. The obtained LSM–Ag composite powders were characterized by XRD, SEM, EDX, and STEM. The results showed that the LSM–Ag composite powder possess an elaborated fine structure with a homogeneous distribution of Ag and LSM, which effectively shortens the diffusion pathway for electrons and adsorbed oxygen. The electrochemical performance of the LSM–Ag cathode with different Ag loadings was investigated. A cathode loading with 1 wt.% Ag exhibited an area specific resistance as low as 0.45 Ω cm2 at 750 °C, compared to around 1.1 Ω cm2 for a pure LSM electrode. Similarly an anode-supported SOFC with 1 wt.% Ag in the cathode shows a peak power density of 1199 mW cm−1, higher than the value of 717 mW cm−1 achieved for a similar cell with a LSM cathode. Increasing the Ag loading is shown to have an insignificant effect on improving electrocatalytic performance at 750 °C, however it can increase output power at 650 °C. [Copyright &y& Elsevier]

The phenomenon of flexoelectricity, wherein mechanical deformation induces alterations in the electron configuration of metal oxides, has emerged as a promising avenue for regulating electron transport. Leveraging this mechanism, stress sensing can be optimized through precise modulation of electron transport. In this study, the electron transport in 2D ultra-smooth In 2 O 3 crystals is modulated via flexoelectricity. By subjecting cubic In 2 O 3 (c-In 2 O 3 ) crystals to significant strain gradients using an atomic force microscope (AFM) tip, the crystal symmetry is broken, resulting in the separation of positive and negative charge centers. Upon applying nano-scale stress up to 100 nN, the output voltage and power values reach their maximum, e.g. 2.2 mV and 0.2 pW, respectively. The flexoelectric coefficient and flexocoupling coefficient of c-In 2 O 3 are determined as ≈0.49 nC m -1 and 0.4 V, respectively. More importantly, the sensitivity of the nano-stress sensor upon c-In 2 O 3 flexoelectric effect reaches 20 nN, which is four to six orders smaller than that fabricated with other low dimensional materials based on the piezoresistive, capacitive, and piezoelectric effect. Such a deformation-induced polarization modulates the band structure of c-In 2 O 3 , significantly reducing the Schottky barrier height (SBH), thereby regulating its electron transport. This finding highlights the potential of flexoelectricity in enabling high-performance nano-stress sensing through precise control of electron transport., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)