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The ionic conductivity for single beads of spherical nickel hydroxide in KOH solutions was determined, using a specially designed device. The refined model is supported by the influence of KOH concentration in bulk on chronoamperometry and transmission electron microscopy observations.

The insight into the Cu-ZnO interaction under different gas conditions by combining the in situ transmission electron microscopy (TEM) results with in situ electron energy loss spectroscopy (EELS) measurements is investigated. Variations in the energy loss near edge structure (ELNES) intensity at the Cu L3 edge are interpreted as a tensile strain in the Cu nanoclusters induced by the ZnO support and a Cu-Zn alloy formation at the Cu/ZnO interface induced by increasing the reduction potential in the gas phase.

A rotating disk electrode (RDE) with an interchangeable Au substrate is used that might be removed after Pd deposition for characterization using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The possible origin of the high activity of Pd nanorods toward the ORR is discussed based on the combination of electrochemical experiments and density functional theory calculations.

The preparation of ultrafine Pt/C catalysts with the Pt particle size reduced to about 1 nm and the resulting changes in the crystalline structure, electronic structure, and catalytic activity toward hydrogen oxidation reaction (HOR) are described. The results have provided insights into the catalyst design of fuel cells and heterogeneous catalytic processes.

An approach is described that has directly established the synergistic effect between surfaces when brought into close proximity through the use of a scanning tunneling microscope (STM). This approach is applied to the electrocatalytic oxidation of CO.

Potential step measurement is performed on single beads of spherical nickel hydroxide to determine the proton diffusion coefficient (D) and concentration of the effective proton vacancies (C). The semi-infinite diffusion equation for the initial stage and the finite diffusion equation for the long-term of the current response to potential step are used for deducing the D and C values.

Two 3d-4d heteropolynuclear clusters with Ag-Zn ratios of 9:2 and 9:4 were stepwise constructed from a robust nonanuclear silver cluster. Their crystal structures consist of a common bucket-shaped [Ag9(mba)9]9- (H2mba = 2-mercaptobenzoic acid) core with different numbers of ZnII connected by different exo-oriented carboxylates. Most fascinating is the observation of emission (~703 nm) in the near-infrared (NIR) region at 300 K that may be compared to the related Ag9Zn3 cluster with aliphatic polyamine as auxiliary ligand that emits from the visible (~580 nm). The shift is associated with the change of ligand field of the 2,2'-bipyridine. The emission intensity and lifetime were dramatically enhanced along with the slight bathochromic shift upon cooling from 300 K to 80 K. The results raise two significant issues: (a) the structural and electronic effects of the secondary metal binding to the metalloligand and the factors influencing the heteropolynuclear cluster assembly and (b) the use of NIR fluorescence, introduced by integrating two luminophores into one heteropolynuclear entity, in detecting free-moving zinc in biological systems both in vivo and in vitro. [ABSTRACT FROM AUTHOR]

The forced water–oil displacement in capillary is a model that has important applications such as the groundwater remediation and the oil recovery. Whereas it is difficult for experimental studies to observe the displacement process in a capillary at nanoscale, the computational simulation is a unique approach in this regard. In the present work, the many-body dissipative particle dynamics (MDPD) method is employed to simulate the process of water–oil displacement in capillary with external force applied by a piston. As the property of all interfaces involved in this system can be manipulated independently, the dynamic displacement process is studied systematically under various conditions of distinct wettability of water in capillary and miscibility between water and oil as well as of different external forces. By analyzing the dependence of the starting force on the properties of water/capillary and water/oil interfaces, we find that there exist two different modes of the water–oil displacement. In the case of stronger water–oil interaction, the water particles cannot displace those oil particles sticking to the capillary wall, leaving a low oil recovery efficiency. To minimize the residual oil content in capillary, enhancing the wettability of water and reducing the external force will be beneficial. This simulation study provides microscopic insights into the water–oil displacement process in capillary and guiding information for relevant applications. [ABSTRACT FROM AUTHOR]

Pd has been the focus of recent research for Pt-alternative catalysts for the oxygen reduction reaction (ORR). It has been found that upon appropriate modification of its electronic structure, the catalytic activity of Pd can become comparable to that of Pt. However, the structure-activity relationships of Pd catalysts have hitherto not been well studied or understood. In the present work, we report a new finding that there is a strong dependence of the activity of Pd toward the ORR on its morphology. By simply adjusting the precursor concentration in the electrochemical deposition of Pd, we are able to tailor the morphology of the deposited Pd from nanoparticles to nanorods. Surprisingly, the surface-specific activity of Pd nanorods (Pd-NR5) toward the ORR was found to be not only 10-fold higher than that of Pd nanoparticles (Pd-NPs), the conventional shape of electrocatalysts, but also comparable to that of Pt at operating potentials of fuel cell cathodes. The morphology-activity relationships of Pd-NRs were further studied through a combination of electrochemical experiments and density functional theory (DFT) calculations. As revealed by its characteristic profile for CO stripping, the morphology of Pd-NRs features the exposure of Pd(1 10) facets, which exhibit superior ORR activity. The underlying mechanism, indicated by DFT calculations, could be ascribed to the exceptionally weak interaction between an 0 adatom and a Pd(1 10) facet. This finding furthers our understanding of Pd catalysis and casts a new light on the relevant catalyst design criteria. [ABSTRACT FROM AUTHOR]

Two three-dimensional 2p—3d—4f hetero- metallic frameworks featuring a nanosized Ln6Cu24Na12 (Ln = Gd, Dy) cluster as a node have been obtained under microwave irradiation conditions through the reaction of H2ANMA (H2ANMA = L-alanine-N-monoacetic acid), Cu-(NO3)2, and Ln(NO3)3 (Ln = Gd for 1, Dy for 2) with NaOH in deionized water. Investigations on the magnetic properties show that 1 exhibits ferrimagnetic behavior. The electrical conductivity measurements reveal that 1 behaves as a proton conductor. [ABSTRACT FROM AUTHOR]