Driven by the rising demand for consumer electronics, the field of all solid-state batteries employing solid electrolytes as the ion-conducting separator has attracted enormous attention in the last years. Recently, the lithium-conducting rare-earth halides A 3 MX 6 (A = Li, M = Y, Er, X = Cl, Br, I) and Li 3 InX 6 have been rediscovered as potential solid electrolytes, showing a good overall electrochemical performance, while the corresponding sodium-based compounds have been mostly overlooked yet. Here, we report the ionic transport properties of the Na-ion conducting rare-earth halide solid electrolyte Na 3−x Er 1−x Zr x Cl 6 . Na 3−x Er 1−x Zr x Cl 6 shows a conductivity enhancement from 10 −9 S•cm −1 up to of ∼0.04 mS•cm −1 for Na 2.4 Er 0.4 Zr 0.6 Cl 6 , alongside interesting local structural rearrangements of the polyhedral motifs along the series of solid solutions. This series of halide-based sodium-ion conductors sheds light on promising compositions in search for superionic materials.

Nanoparticles in solution interact with their surroundings via hydration shells. Although the structure of these shells is used to explain nanoscopic properties, experimental structural insight is still missing. Here we show how to access the hydration shell structures around colloidal nanoparticles in scattering experiments. For this, we synthesize variably functionalized magnetic iron oxide nanoparticle dispersions. Irrespective of the capping agent, we identify three distinct interatomic distances within 2.5 Å from the particle surface which belong to dissociatively and molecularly adsorbed water molecules, based on theoretical predictions. A weaker restructured hydration shell extends up to 15 Å. Our results show that the crystal structure dictates the hydration shell structure. Surprisingly, facets of 7 and 15 nm particles behave like planar surfaces. These findings bridge the large gap between spectroscopic studies on hydrogen bond networks and theoretical advances in solvation science.

Mesoporous nitrogen-doped silicon carbide catalysts with integrated cobalt nanoparticles (Co@N-SiC) were synthesized by the thermal decomposition of a microphase-separated block copolymer of polycarbosilane and polyethylene. The catalysts are highly active, reusable and offer selective hydrogenation of the nitro group in the presence of hydrogenation-sensitive functional groups.

Applications in biomedicine and ferrofluids, for instance, require long-term colloidally stable, concentrated aqueous dispersions of magnetic, biocompatible nanoparticles. Iron oxide and related spinel ferrite nanoparticles stabilized with organic molecules allow fine-tuning of magnetic properties via cation substitution and water-dispersibility. Here, we synthesize � 5 nm iron oxide and spinel ferrite nanoparticles, capped with citrate, betaine and phosphocholine, in a one-pot strategy. We present a robust approach combining elemental (CHN) and thermal gravimetric analysis (TGA) to quantify the ratio of residual solvent molecules and organic stabilizers on the particle surface, being of particular accuracy for ligands with heteroatoms compared to the solvent. SAXS experiments demonstrate the long-term colloidal stability of our aqueous iron oxide and spinel ferrite nanoparticle dispersions for at least 3 months. By the use of SAXS we approved directly the colloidal stability of the nanoparticle dispersions for high concentrations up to 100 g L À 1. [a

Dedicated to Prof. Dr. Josef Breu on the occasion of his 60th birthdayPhase-pure 6 nm spinel MnFe 2 O 4 nanoparticles with high specific surface area of 145 m 2 g À 1 were successfully prepared via microwave-assisted non-aqueous sol-gel synthesis. The phase evolution during postsynthetic thermal treatment was investigated systematically by various methods, including powder X-ray diffraction (PXRD), pair distribution function (PDF) analysis, and Raman spectroscopy. Our results show that the material decomposes to non-spinel binary compounds α-Mn 2 O 3 and α-Fe 2 O 3 at temperatures between 400 and 600 °C. The application potential of MnFe 2 O 4 nanoparticles with 3d 5 Mn(II) and Fe(III) ions with respect to the magnetic properties was demonstrated by superconducting quantum interference device (SQUID) magnetometry, with the as-synthesized nanoparticles reaching a high saturation magnetization of 2.62 μ B per formula unit (63.5 Am 2 kg À 1 ) at 10 K. We further highlight the visiblelight response of synthesized powders, making the materials promising for light-related applications, e. g. photocatalytic hydrogen evolution. An important additional feature of MnFe 2 O 4 nanoparticles is their good dispersibilty in polar or non-polar media, as a result of postsynthetic colloidal stabilization with betaine hydrochloride, oleic acid combined with oleylamine, or citric acid.