Hydrothermal synthesis and thermoelectric transport properties of impurity-free antimony telluride hexagonal nanoplates

Impurity-free single-crystalline antimony telluride hexagonal nanoplates (see figure) are synthesized by a facile and quick hydrothermal treatment without any organic additives or templates. The inherent crystal structure is the driving force for the growth of these Sb2Te3 hexagonal nanoplates. Films of these nanoplates shows p-type behavior, and exhibit a promisingly high Seebeck coefficient of 425 mu V K-1 at room temperature.

Hydrothermal synthesis and photoluminescent properties of stacked indium sulfide superstructures

Unusual hierarchical stacked superstructures of cubic beta-In2S3 were fabricated via a facile hydrothermal process in the presence of a surfactant cetyltrimethylammonium bromide CTAB; the 3D superstructures were developed by helical propagation of surface steps from microflakes of 10-20 nm thickness.

A general method for the rapid synthesis of hollow metallic or bimetallic nanoelectrocatalysts with urchinlike morphology

We have reported a facile and general method for the rapid synthesis of hollow nanostructures with urchinlike morphology. In-situ produced Ag nanoparticles can be used as sacrificial templates to rapidly synthesize diverse hollow urchinlike metallic or bimetallic (such as Au/Pt) nanostructures. It has been found that heating the solution at 100 degrees C during the galvanic replacement is very necessary for obtaining urchinlike nanostructures. Through changing the molar ratios of Ag to Pt, the wall thickness of hollow nanospheres can be easily controlled; through changing the diameter of Ag nanoparticles, the size of cavity of hollow nanospheres can be facilely controlled; through changing the morphologies of Ag nanostructures from nanoparticle to nanowire, hollow Pt nanotubes can be easily designed. This one-pot approach can be extended to synthesize other hollow nanospheres such as Pd, Pd/Pt, Au/Pd, and Au/Pt. The features of this technique are that it is facile, quick, economical, and versatile.

Vilsmeier Reaction of Enaminones: Efficient Synthesis of Halogenated Pyridin-2(1H)-ones

A facile and efficient one-pot synthesis of halogenated pyridin-2(1H)-ones from a series of readily available enaminones under Vilsmeier conditions is described, and a mechanism involving sequential halogenation, formylation, and intramolecular nucleophilic cyclization is proposed.

Ionic liquid-based "all-in-one" synthesis and photoluminescence properties of lanthanide fluorides

A facile route to the synthesis of LnF(3) nanocrystals has been accomplished in three ionic liquids (ILs) (OmimPF(6), OmimBF(4), and BmimPF(6)). The partial hydrolysis of PF6- and BF4- was utilized to introduce a new fluoride source. Uniform LnF(3) (Ln = La, Ce, Pr, Nd, Sm, Eu, Er), Tb3+-doped CeF3, and Eu3+-doped LaF3 nanocrystals could be obtained in a large scale, and the products were up to 0.15 g per 10 mL solvents. In the "all-in-one" systems, the ILs acted as solvents, reaction agents, and templates.

Selective, peroxidase substrate based "signal-on" colorimetric assay for the detection of chromium (VI)

Due to the potentially adverse effects of the chromium (VI) on the human health and also on the environment, the quantitative determination of Cr(VI) is of particular interest. This work herein reports a facile, selective and rapid colorimetric determination of Cr(VI) based on the peroxidase substrate-2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) as the color developing agent. ABTS, which was usually acted as peroxidase substrate for the enzyme linked immunosorbent assay, is used here for the first time to fabricate the "signal-on" colorimetric Assay for Cr(VI).

Direct Electrochemistry and Electrocatalysis of Hemoglobin in Lipid Film Incorporated with Room-Temperature Ionic Liquid

A facile phospholipid/room-temperature ionic liquid (RTIL) composite material based on dimyristoylphosphatidylcholine (DMPC) and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) was exploited as a new matrix for immobilizing protein. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were adopted to characterize this composite film. Hemoglobin (Hb) was chosen as a model protein to investigate the composite system. UV-vis absorbance spectra showed that Hb still maintained its heme crevice integrity in this composite film.

Hydrothermal synthesis of lanthanide fluorides LnF(3) (Ln = La to Lu) nano-/microcrystals with multiform structures and morphologies

Lanthanide fluoride LnF(3) (Ln = La to Lu) nano-/microcrystals with multiform crystal structures (hexagonal and orthorhombic) and morphologies (separated elongated nanoparticles, aggregated nanoparticles, polyhedral microcrystals) were successfully synthesized by a facile, effective, and environmentally friendly hydrothermal method. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and photoluminescence spectra were used to characterize the samples. The experimental results indicated that the use of NaBF4 is indispensable for obtaining LnF(3) crystal structures.

Shape controllable synthesis and upconversion properties of NaYbF4/NaYbF4 : Er3+ and YbF3/YbF3 : Er3+ microstructures

Ytterbium fluoride compounds with different crystal phases and morphologies, such as beta-NaYbF4 hexagonal microdisks, microprisms, microtubes, and alpha-NaYbF4 submicrospheres as well as YbF3 octahedra, have been synthesized via a facile hydrothermal route. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and photoluminescence (PL) spectra were used to characterize the samples.

Uniform Colloidal Alkaline Earth Metal Fluoride Nanocrystals: Nonhydrolytic Synthesis and Luminescence Properties

In this paper, we present a facile and general synthetic route to high-quality alkaline earth metal fluoride (AEF(2), AE = Ca, Sr, Ba) nanocrystals and CaF2:Tb3+ nanocrystals based on the thermal decomposition of corresponding trifluoroacetate precursors in hot oleylamine. X-ray diffraction, transmission electron microscopy, thermogravimetric and differential thermal analysis, Fourier transform infrared spectra, photoluminescence spectra, and kinetic decays were employed to characterize the samples. The use of single-source precursors plays an important role in the formation of high-quality AEF(2) nanocrystals, and the formation process is demonstrated in detail.

Polyol-Mediated Synthesis of PbS Crystals: Shape Evolution and Growth Mechanism

An interesting shape evolution of. PbS crystals, that is, from cubes to (truncated) octahedra and finally to stable star-shaped multipods with six arms along the < 100 > directions is first realized via a facile polyol-mediated reaction between lead acetate and sulfur powder in the absence of surfactants. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) techniques were employed to characterize the samples. We elucidate the important parameters (including reaction temperature and sulfur sources) responsible for the shape-controlled synthesis of PbS crystals.

Highly Uniform and Monodisperse Ba2CIF3 Microrods: Solvothermal Synthesis and Characterization

One-dimensional hexagonal Ba2CIF3 microrods with highly uniform morphology and size have been successfully synthesized via a facile solvothermal method at a low temperature (160 degrees C). X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the samples. The synthesis process, based on a phase-transfer and separation mechanism, allows the control of properties such as particle size and shape in low dispersity by bonding the surfactant oleic acid to the crystal surface.

One-step aqueous solvothermal synthesis of In2O3 nanocrystals

Highly crystalline and nearly monodisperse In2O3 nanocrystals with both cube and flower shapes were successfully synthesized in one step through a facile aqueous solvothermal method for the first time, free of any surfactant or template. X-ray diffraction (XRD), transmission electron microscopy (TEM), selective area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM) were used to characterize the samples. In our work, the use of diethylene glycol (DEG) is a crucial factor for the formation of the In2O3 phase.

Large-area silver-coated silicon nanowire arrays for molecular sensing using surface-enhanced Raman spectroscopy

A new and facile method to prepare large-area silver-coated silicon nanowire arrays for surface-enhanced Raman spectroscopy (SERS)-based sensing is introduced. High-quality silicon nanowire arrays are prepared by a chemical etching method and used as a template for the generation of SERS-active silver-coated silicon nanowire arrays. The morphologies of the silicon nanowire arrays and the type of silver-plating solution are two key factors determining the magnitude of SERS signal enhancement and the sensitivity of detection; they are investigated in detail for the purpose of optimization.

Environmentally friendly synthesis of highly monodisperse biocompatible gold nanoparticles with urchin-like shape

We report a facile and environmentally friendly strategy for high-yield synthesis of highly monodisperse gold nanoparticles with urchin-like shape. A simple protein, gelatin, was first used for the control over shape and orientation of the gold nanoparticles. These nanoparticles, ready to use for biological systems, are promising in the optical imaging-based disease diagnostics and therapy because of their tunable surface plasmon resonance (SPR) and excellent surface-enhanced Raman scattering (SERS) activity.