Microwave synthesis of fluorescent carbon nanoparticles with electrochemiluminescence properties

We present a facile, economical microwave pyrolysis approach to synthesize fluorescent carbon nanoparticles with electrochemiluminescence properties.

Shape and Phase-Controlled Synthesis of KMgF3 Colloidal Nanocrystals via Microwave Irradiation

In this paper, we present a facile one-step route to controlled synthesis of colloidal KMgF3 nanocrystals via the thermolysis of metal trifluoroacetate precursors in combined solvents (OA/OM) using microwave irradiation. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric and differential thermal analysis (TG-DTA), Fourier transform infrared (FT-IR) spectra, and photoluminescence (PL) spectra were employed to characterize the samples. Only through the variation of the OA/OM ratio, can the phase and shape of nanocrystals be readily controlled, resulting in the formation of well-defined near-spherical nanoparticles, and nanoplates of cubic-phased KMgF3, as well as nanorods of tetragonal-phased MgF2, and a possible mechanism has been proposed to elucidate this effect. Furthermore, all these samples in this system can be well dispersed in nonpolar solvents such as cyclohexane to form stable and clear colloidal solutions, due to the successful coating of organic surfactants (OA/OM) on the nanocrystal surface.

Shape-Controlled Synthesis of Wurtzite ZnS Microstructures Under Mild Solvothermal Condition

Through a facile solvothermal route using zinc chloride and thiourea as reactants, wurtzite ZnS and its precursor ZnS center dot (en)(0.5) (en = ethylenediamine) with various morphologies and sizes were grown, which were characterized by XRD, SEM, TEM and N-2 adsorption and so on. The phase evolution, composition and morphologies of the products are highly dependent on the concentration of en. By keeping the en-water volume ratio at 1/2 to 1, the nanostripes-flower or nanorod-spheric wurtzite ZnS were easily obtained under 120 degrees C for 6-24 h, which possess relatively higher specific surface area and larger total pore volume.

Synthesis and characterization of Eu-doped hydroxyapatite through a microwave assisted microemulsion process

Europium doped hydroxyapatite (Eu:HAp) nanosized particles with multiform morphologies have been successfully prepared via a simple microemulsion-mediated process assisted with microwave heating. The physicochemical properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra, and the kinetic decays, respectively. The results reveal that the obtained Eu:HAp particles are well assigned to the hexagonal lattice structure of the hydroxyapatite phase. Additionally, it is found that samples exhibit uniform morphologies which can be controlled by altering the pH values. Furthermore, the samples show the characteristic D-5(0)-F-7(1-4) emission lines of Eu3+ excited by UV radiation.

Rapid synthesis of hexagon-shaped gold nanoplates by microwave assistant method

The microwave (MW)-based thermal process was applied to the preparation of hexagon-shaped gold nanoplates. The fort-nation of gold nanoplates occurs rapidly in a single step, carried out by directly heating a reaction mixture of HAuCl4 with sodium citrate in an MW reactor. And the gold nanoplates were characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experimental results indicated that the sizes and morphologies of the gold nanomaterials strongly depend both on the heating methods and molar ratio of HAuCl4 to sodium citrate in the initial reaction mixture. At the molar ratio 5 : 4 (HAuCl4 to sodium citrate), hexagonal nanoplates with large Au (111) crystallographic facet were preferentially synthesized by the MW assistant method.

Synthesis of the complex fluoride LiBaF3 and optical spectroscopy properties of LiBaF3 : M(M = Eu,Ce) through a solvothermal process

The complex fluoride LiBaF3 and LiBaF3:M(M = Eu, Ce) is solvothermally synthesized at 180 degreesC and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, molar ratios of initial mixtures and reaction temperature play important roles in the formation of products. The excitation and emission spectra of the LiBaF3:M(M= Eu,Ce) have been measured by fluorescence spectrophotometer. In the LiBaF3: Eu emission spectra, there is one sharp line emission located at 360 nm arising from f --> f transition of Eu2+ in the host lattice, and typical doublet 5d-4f emission of Ce3+ in LiBaF3 powder is shown.

Synthesis of the complex fluoride LiBaF3 through a solvothermal process

The complex fluoride LiBaF3 is solvothermally synthesized at 180degreesC and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, mole ratios of initial mixtures and reaction temperature play important roles in the growth of the single crystal.

Synthesis of a high-permeance NaA zeolite membrane by microwave heating

Zeolite membranes with high permeance and separation factors are highly desirable for practical applications. Although, in the past, very good separation factors have been obtained, it has proved difficult to achieve a high permeance. Ken a comparative study of microwave versus conventional heating in the hydrothermal synthesis of NaA zeolite membranes is made. It is demonstrated that membranes prepared by microwave heating have not only a higher permeance but also a considerably shorter synthesis time. These observations are rationalized by examining the mechanism of membrane formation.

Synthesis of NaA zeolite membrane by microwave heating

The synthesis of NaA zeolite membrane on a porous alpha -Al2O3 support by microwave heating (MH) was investigated. The formation of a NaA zeolite membrane was drastically promoted by MH. The synthesis time was reduced from 3 h for conventional heating (CH) to 15 min for MH. Surface seeding cannot only promote the formation of NaA zeolite on the support, but also inhibit the transformation of NaA zeolite into other types of zeolites. The thickness of the NaA zeolite membrane synthesized by MH was about 4 mum, thinner than that of NaA zeolite membrane synthesized by CH. The permeance of NaA zeolite membrane synthesized by MH was four times higher than that of the NaA zeolite membrane synthesized by CH, while their permselectivities were comparable. Multi-stage synthesis resulted in the transformation of NaA zeolite into other types of zeolites, and the perfection of the as-synthesized membrane decreased.

Synthesis of Cu-In-S ternary nanocrystals with tunable structure and composition

Nearly monodisperse Cu-In-S ternary nanocrystals with tunable composition, crystalline structure, and size were synthesized by a hot-injection method using mixed generic precursors. Such ternary nanocrystals with zincblende and wurtzite structure were reported for the first time.

Synthesis and characterization of (Zn,Cd)TiO3 by a modified sol-gel method

Ilmenite-type (Zn1-xCdx)TiO3 (0 <= x <= 0.15 and 0.8 <= x <= 1.0) was synthesized by a modified sol-gel route including the Pechini process via two-step heat treatments. The thermal stability of (Zn1-xCdx)TiO3 depended on the amount of cadmium content. The as-synthesized (Zn1-xCdx)TiO3 (0 <= x <= 0.15 and 0.8 <= x <= 1.0) showed higher thermal stability than that of ZnTiO3. The variation of the dielectric constant of all synthesized (Zn1-xCdx)TiO3 samples for all measurement frequencies showed a similar tendency.

Synthesis and characterization of 1D Co/CoFe2O4 composites with tunable morphologies

1D Co/CoFe2O4 composites with tunable morphologies were fabricated by a facile solvothermal route in the presence of a surfactant poly(vinylpyrrolidone) (PVP); they may be very attractive for potential applications because of their outstanding soft magnetism.

3D Fe3S4 flower-like microspheres: high-yield synthesis via a biomolecule-assisted solution approach, their electrical, magnetic and electrochemical hydrogen storage properties

Well-defined 3D Fe3S4 flower-like microspheres were synthesized via a simple biomolecule-assisted hydrothermal process for the first time. On the basis of a series of contrast experiments, the probable growth mechanism and fabrication process of the products were proposed. The electrical conductivity property of the as-synthesized Fe3S4 sample exhibited a rectifying characteristic when a forward bias was applied for the bottom-contacted device. The magnetic properties of the products were studied as well and the results demonstrated that the products presented ferromagnetic properties related to the corresponding microstructure. In addition, we first verified that the Fe3S4 flower-like microspheres could store hydrogen electrochemically, and a discharge capacity of 214 mA h g(-1) was measured without any activation under normal atmospheric conditions at room temperature.