961 resultados para FACILE SYNTHESIS
Resumo:
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.
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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.
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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.
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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.
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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.
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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.
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Nanostructured CaWO4, CaWO4:Eu3+, and CaWO4:Tb3+ phosphor particles were synthesized via a facile sonochemical route. X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, low voltage cathodoluminescence spectra, and photoluminescence lifetimes were used to characterize the as-obtained samples. The X-ray diffraction results indicate that the samples are well crystallized with the scheelite structure of CaWO4.
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This paper describes a facile route for simultaneous synthesis of polyaniline (PANI) nanotubules and gold nanoplates. The inner diameter of PANI nanotubules was less than 10 nm and the length was several micrometers. At the same time, uniform single-crystal gold nanoplates with thicknesses of tens of nanometers were obtained.
Resumo:
Monodispersed KY3F10:Eu3+ nanospheres with bimodal size distribution have been successfully synthesized via a facile and efficient sonochemical method in a surfactant-free system. Rare-earth nitrate (Y, Eu)(NO3)(3) and potassium fluoborate (KBF4) were used as precursors. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and photoluminescence (PL) spectra were used to characterize the samples.
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We present a facile, economical microwave pyrolysis approach to synthesize fluorescent carbon nanoparticles with electrochemiluminescence properties.
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Well-dispersed YVO4:Ln(3+) (Ln = Eu, Dy, and Sm) nanocrystals with uniform morphology and size have been synthesized via a facile solvothermal route. XRD results demonstrate that all of the three samples can be well indexed to the pure tetragonal phase Of YVO4, indicating that the Eu3+, Dy3+, and Sm3+ have been effectively doped into the host lattices of YVO4. TEM images show that the YVO4 nanocrystals exhibit ellipsoid shape and a mean size of about 20 nm, which is in good agreement with the estimation of XRD results.
Resumo:
One-dimensional La(OH)(3) nanocrystals with multiform morphologies have been successfully synthesized by a facile bydrothermal process without using any surfactant, catalyst, or template. It can be found that the pH values of the initial solutions and the alkaline sources play a crucial role in controlling the morphologies of the products. The possible formation process of the 1D samples was investigated in detail, Furthermore, the as-prepared Tb3+-doped La(OH)(3) samples show a strong green emission corresponding to D-5(4)-F-7(5) transition of the Tb3+ ions under ultraviolet or low-voltage excitation.
Resumo:
The facile, rapid, and effective synthesis of coordination polymer La(1,3,5-BTC)(H2O)(6) has been realized via direct precipitation at room temperature. It is found that the crystal structure is of monoclinic, space group Cc. The doped Eu3+ or Tb3+ ions samples have the same phase and exhibit red and green emissions under UV light excitation, respectively.
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In this article, a two-dimensional (2D) nanoplate and a 3D hierarchical structure of BiOCl were synthesized through a simple sonochemical route. Compared with previous preparation methods, the 2D nanoplates can be prepared at a relatively short time (about 30 min) with low energy used. Additionally, these 2D nanoplates can easily assemble into a 3D hierarchical structure with the surfactant reagents. The obtained products were well crystallized and subsequently characterized by a range of methods, such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission microscopy (HRTEM), selected area electron diffraction (SAED) and Raman spectroscopy.
Resumo:
Lanthanum phosphate (LaPO4) nanostructures with different morphologies were prepared by a facile solution-precipitation process. The effect of different reaction conditions on the morphology of nanostructures was studied. When the molar ratio of La3+:H3PO4 was around 1 : 2, 1 : 20, 1 : 100, and 1 : 200, four different morphologies, such as near-spherical, snowflake-like, star-shaped, lens-like nanostructures and short nanorods, were obtained, respectively. Meanwhile, similar shapes developed when the molar ratio of H3PO4 to ionic surfactants, such as SDS and CTAB, was varied. In addition, Eu3+ doped and Ce3+/Tb3+ co-doped LaPO4 nanostructures showed morphology evolution similar to undoped LaPO4 nanostructures. The optical properties of these doped LaPO4 were also characterized.