Synthesis of LaF3 nanosheets with high fluorine mobility investigated by NMR relaxometry and diffusometry.

Ionically conducting lanthanum fluoride (LaF3), displaying a nanoscopic lamellar structure, has been synthesized at the surface of an aqueous solution of LaCl3 and HF. The structure and the chemical composition of the conductor have been analyzed by SEM, electron probe microanalysis, X-ray powder diffraction, FTIR, and (19)F magic angle spinning nuclear magnetic resonance (NMR) spectroscopy. The fluorine dynamics have been studied by NMR diffusometry and relaxometry in a temperature range from room temperature up to 875 K. The fluorine self-diffusion coefficient of the nanostructured LaF3 is about two orders of magnitude larger than that of bulk LaF3. This novel material is highly promising for many typical applications of fluorine ionic systems.

Peroxide route to the synthesis of ultrafine CeO2-Fe2O3 nanocomposite via successive ionic layer deposition.

An ultrafine α-CeO2-α-Fe2O3 nanocomposite was prepared from the ultradispersed nanoparticles of cerium (IV) and iron (III) amorphous hydroxides heat-treated at 600 °Ð¡ and 900 °Ð¡ in the air. The initial composites were obtained by the successive ionic layer deposition (SILD) method. According to scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD), the cerium/iron ratio in the synthesized nanocomposite is close to 1:2, and the α-CeO2 and α-Fe2O3 nanocrystals are isometrically shaped and have an average size of 4 ± 1 and 7 ± 1 nm (600 °Ð¡) and 24 ± 2 and 35 ± 3 nm (900 °Ð¡), respectively. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) have shown that nanocrystals are evenly distributed in the composite volume and are spatially conjugated. The formation mechanisms of both initial amorphous composites of cerium (IV) and iron (III) hydroxides and of α-CeO2 and α-Fe2O3 nanocrystals were established. It was shown that synthesis of the initial hydroxide composite using the SILD method proceeds via the formation of amorphous cerium hydroxo-peroxide (CeO(OOH)2). As a result of the study, a schematic mechanism for the formation of a composite based on ultrafine nanocrystals of cerium (IV) and iron (III) oxides has been proposed.

Synthesis of 2D Zn-Co LDH nanosheets by a successive ionic layer deposition method as a material for electrodes of high-performance alkaline battery-supercapacitor hybrid devices.

In recent years, increasing attention directed at creating novel two-dimensional graphene-like materials, in particular materials based on oxides or hydroxides of transition metals, as they have a number of unique properties, which determine the perspective of their application in various fields of electronics and electrical engineering, as well as in energy storage devices. In this paper we propose a novel promising route for the synthesis of nanolayer layered double hydroxides on the basis of zinc and cobalt by a successive ionic layer deposition method. The obtained nanolayers were characterized by SEM, EDX, XRD, HRTEM, XPS and FT-IR. The results show the synthesized nanolayers were formed from two-dimensional nanocrystals with the thickness of about 6-9 nm and the morphology of the so-called "nanosheets" with the hydrotalcite-like crystal structure of an LDH. In addition, the obtained nanolayers were investigated as electrode materials for alkaline battery-supercapacitor hybrid devices and demonstrated a high specific capacitance (270 mA h g-1 at 1 A g-1) and excellent electrochemical stability (3% drop in capacity after 1000 charge-discharge cycles).