Liquid-crystalline phases in liquid ammonia were used to obtain meso- and microporous Si3N4, TiN, and VN. The liquid-crystalline phase was established at -50 degrees C with liquid ammonia as the polar phase, heptane as the nonpolar dispersant phase, dimethyldioctylammonium iodide (DDAI) as the surfactant, and heptylamine as the cosurfactant. Silicon(IV) iodide, tetrakis(dimethylamino)titan, and vanadium(IV) chloride were added and ammonolyzed in the liquid-crystalline phase. After the mixture contents were separated and washed, ammonolysis was completed by slow heating to 600 degrees C (TiN, VN) and 800 degrees C (Si3N4) in vacuum or forming gas (N2/H2). The obtained high-surface nitrides are characterized by high purity (e.g., Si3N4 with carbon content <3 at %), great specific surface area (Si3N4: 610 m(2)/g; TiN: 203 m(2)/g; VN: 63 m(2)/g), and great total pore volume (Si3N4: 1.5 cm(3)/g; TiN: 0.3 cm(3)/g; VN: 0.4 cm(3)/g). Si3N4 and TiN show considerable meso- and microporosity, whereas the less-stable VN only shows mesoporosity. Electron energy loss spectroscopy (EELS) proves low oxygen contents. As a proof-of-concept, uniform one-pot modification of Si3N4 with Pd nanoparticles (Pd@Si3N4) as well as the reversible hydrogen sorption of differently treated Si3N4 were studied, which results in a maximum H2 uptake of 2.5 wt % (at 25 degrees C, 40 bar).

The catalytic activity of Pd‐SnO2 core@shell nanocomposites in the oxidation of CO and their CO‐sensing behavior were compared. For this purpose, Pd particles were placed on the inside and the outside of SnO2 hollow spheres, as demonstrated by electron tomography, X‐ray photoelectron spectroscopy, and X‐ray absorption spectroscopy. Both the sensing and catalytic effect were studied in a systematic manner on such nanocomposites, and striking differences in the catalytic performance of the nanocomposites in CO oxidation and CO and H2 sensing were found. At low temperatures, SnO2@Pd was found to be a good sensor, and the light‐off temperature was significantly lower than that of Pd@SnO2. Above the ignition temperature, CO was probably rapidly removed from the gas so that the sensing effect disappeared. This demonstrated that understanding of the sensing and catalytic behavior can help in unraveling the functional properties of core@shell and Pd‐SnO2 nanocomposites in more detail.

Mo(0), W(0), Fe(0), Ru(0), Re(0), and Zn(0) nanoparticles—essentially base metals—are prepared as a general strategy by a sodium naphthalenide ([NaNaph])-driven reduction of simple metal chlorides in ethers (1,2-dimethoxyethane (DME), tetrahydrofuran (THF)). All the nanoparticles have diameters ≤10 nm, and they can be obtained either as powder samples or long-term stable suspensions. Direct follow-up reactions (e.g., Mo(0)+S8, FeCl3+AsCl3, ReCl5+MoCl5), moreover, allow the preparation of MoS2, FeAs2, or Re4Mo nanoparticles of similar size as the pristine metals (≤10 nm).

On page 907, a gold-titanium dioxide (Au/TiO2) hybrid prepared by L. Fruk and co-workers using a bifunctional bridging linker is shown on this cover image. The bright yellow spots are gold nanoparticles stabilized by a dopamine-lipoic acid derivative, which are then bound to titanium dioxide matrix (purple). This hybrid material shows remarkable catalytical activity towards activation of heme containing enzyme upon light irradiation.

A mild, efficient and ambient temperature photochemical approach for the synthesis of silver nanoparticle core-shell structures employing a zwitterionic polymer as well as polyethylene glycol is presented.

W nanoparticle suspensions in n‐heptane are obtained by reduction of a heptane solution of WCl 6 with Na dissolved in liquid NH 3 (‐50 °C) followed by evaporation of NH 3 and stabilization of nanoparticles by oleylamine as surface capping agent.

Tungsten nanoparticles were obtained from liquid-ammonia-based synthesis via reduction of WCl6 with dissolved sodium. The W(0) nanoparticles exhibit a diameter of 1-2 nm and can be dispersed in alkanes, showing a grayish-orange color due to red-shifted plasmon resonance absorption.

Pd@SnO2 and SnO2@Pd core@shell nanocomposites are prepared via a microemulsion approach. Both nanocomposites exhibit high‐surface, porous matrices of SnO2 shells (>150 m2 g−1) with very small SnO2 crystallites (<10 nm) and palladium (Pd) nanoparticles (<10 nm) that are uniformly distributed in the porous SnO2 matrix. Although similar by first sight, Pd@SnO2 and SnO2@Pd are significantly different in view of their structure with Pd inside or outside the SnO2 shell and in view of their sensor performance. As SMOX‐based sensors (SMOX: semiconducting metal oxide), both nanocomposites show a very good sensor performance for the detection of CO and H2. Especially, the Pd@SnO2 core@shell nanocomposite is unique and shows a fast response time (τ90 < 30 s) and a very good response at low temperature (<250 °C), especially under humid‐air conditions. Extraordinarily high sensor signals are observed when exposing the Pd@SnO2 nanocomposite to CO in humid air. Under these conditions, even commercial sensors (Figaro TGS 2442, Applied Sensor MLC, E2V MICS 5521) are outperformed.

GaN nanoparticles, 3-4 nm in size, are synthesized in a microemulsion using liquid ammonia as the polar droplet phase. Surprisingly, GaN is readily crystalline although prepared at -40 °C. The nanoparticles show a band gap of 4.4 eV as well as light emission with its maximum at 336 nm. Both confirm the expected quantum-confinement effect.

In this study, the nanomorphology of fluorenyl hexa-peri-hexabenzocoronene:[6,6]-phenyl C61-butyric acid methyl ester (FHBC:PC61BM) absorber layers of organic solar cells was investigated. Different electron microscopical techniques, atomic force microscopy, and grazing incidence wide-angle X-ray scattering were applied for a comprehensive nanomorphology analysis. The development of the nanomorphology upon sample annealing and the associated change of the device performance were investigated. It was shown that the annealing process enhances the phase separation and therefore the bulk heterojunction structure. Due to π-π stacking, the FHBC molecules assemble into columnar stacks, which are already present before annealing. While the nonannealed sample consists of a mixture of homogeneously distributed PC61BM molecules and FHBC stacks with a preferential in-plane stack orientation, crystalline FHBC precipitates occur in the annealed samples. These crystals, which consist of hexagonal arranged FHBC stacks, grow with increased annealing time. They are distributed homogeneously over the whole volume of the absorber layer as revealed by electron tomography. The FHBC stacks, whether in the two phase mixture or in the pure crystalline precipitates, exhibit an edge-on orientation, according to results from grazing incidence wide-angle X-ray scattering (GIWAXS), dark-field transmission electron microscopy (DF TEM) imaging and selective area electron diffraction (SAED). The best solar cell efficiencies were obtained after 20 or 40 s sample annealing. These annealing times induce an optimized degree of phase separation between donor and acceptor material.

Flüssiger Ammoniak auf der Nanoskala: Erstmals wird eine Ammoniak-in-Öl-Mikroemulsion vorgestellt, die reproduzierbar und ebenso einfach wie eine konventionelle Wasser-in-Öl-Mikroemulsion verwendet werden kann – mit Ausnahme der für flüssigen Ammoniak notwendigen geringen Temperatur von −40 °C. Als Konzeptstudie wurde die Synthese von Bi0-, Re0-, CoN- und GaN-Nanopartikeln untersucht, und überraschenderweise sind unmittelbar kristalline Nanopartikel ohne weitere thermische Behandlung zugänglich. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Liquid ammonia on the nanoscale: Ammonia-in-oil microemulsions are used to synthesize Bi, Re, CoN, and GaN nanoparticles, which can be obtained without further thermal treatment. These microemulsions are as reproducible and simple as their water-in-oil conterparts, with the exception of the required low temperature of -40 °C.

Using a simple bifunctional bridging linker, nanosized gold and titanium dioxide composites are prepared containing different Au loadings. Linker is synthesized to contain both catechol and thiol moieties to enable binding to the TiO2 and Au surface respectively. Au/TiO2 nanocomposites are prepared using simple synthetic route that allows the control over the amount of Au nanoparticles, a property which plays a significant role in the catalytic activity of hybrid materials. Photocatalytic activity of materials prepared using different TiO2 precursors is investigated using reactive oxygen species sensitive assay based on activation of horseradish peroxidase (HRP) enzyme. Significant increase in catalytic activity is observed for all Au/TiO2 nanocomposites with Au/TiO2 prepared by use of the bridging linker being up to 5.5 times more active than bare commercial TiO2 nanoparticles. In addition to 365 nm light excitation, less energetic 470 nm light, which is more suitable for the use with biological systems, is used to induce photocatalytic activity. Finally, prepared photocatalytic materials are successfully used to exert temporal control over enzymatic activity, a feature which is important for the study of both enzymatic activity and design of novel bio‐sensing platforms.

A water-in-oil microemulsion approach was established to synthesize Pd@SnO2 and SnO2@Pd core@shell nanocomposites in order to investigate the influence of the noble metal additive location on the sensing performance towards CO and H-2 in dry and humid conditions at different temperatures. It turned out that the Pd additive, being either present on the outside of the shells or encapsulated by the SnO2 matrix, strongly influences the sensing performance. Especially, the inner shell Pd doped hollow spheres (Pd@SnO2) have shown very high signals towards CO in humid conditions at rather low sensing operation temperatures together with an almost linear response curve. (C) 2012 Elsevier Ltd....Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.

Nanocrystalline La0.6Sr0.4CoO3-δ thin films with a nominal Sr-content of x=0.4 were deposited on Ce0.9Gd0.1O1.95 electrolyte substrates by low-temperature sol-gel processing. Microstructure, element distribution and electrochemical properties of the LSC thin films were studied after thermal treatment, which included calcination and extended annealing at 700 °C or 800 °C. Transmission electron microscopy combined with Debye electron diffraction and electron tomography was applied for the investigation of the grain-size distribution and porosity. The local chemical composition and element distribution was analyzed by energy-dispersive X-ray spectrometry on the nanoscale. Area specific polarization resistances as low as 0.023 Ωcm2 at 600 °C were measured applying electrochemical impedance spectroscopy. These low resistance values are facilitated by a substantial increase of the inner surface area of the porous thin-film cathode and amplified by an enhanced surface exchange, resulting from precipitation of Co3O4.

Nanocrystalline La1-xSrxCoO3-delta (LSC) thin films with a nominal Sr-content of x = 0.4 were deposited on Ce0.9Gd0.1O1.95 electrolyte substrates using a low temperature sol-gel process. The structural and chemical properties of the LSC thin films were studied after thermal treatment, which included a calcination step and a variable, extended annealing time at 700 degrees C or 800 degrees C. Transmission electron microscopy combined with selected-area electron diffraction, energy-dispersive X-ray spectrometry, and scanning transmission electron microscopy tomography was applied for the investigation of grain size, porosity, microstructure, and analysis of the local chemical composition and element distribution on the nanoscale. The area specific resistance (ASR) values of the thin film LSC cathodes, which include the lowest ASR value reported so far (ASR(chem) = 0.023 Omega cm(2) at 600 degrees C) can be interpreted on the basis of the structural and chemical characterization.