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.

Synthesis and Characterization of Urea Bridged Hybrid Periodic Mesoporous Organosilica Materials

Urea bridged organic-inorganic hybrid mesoporous SiO2 materials (U-BSQMs) were synthesized through a sol-gel procedure by co-condensation of bis(triethoxysilyl propyl) urea (BSPU) under basic conditions using cetyltrimethylammonium bromide (CTAB) as organic template. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the mesoporous structure of the sample. Fourier-transform infrared spectroscopy (FT-IR), solid state CP-MAS NMR spectroscopy of Si-29 (Si-29, CP-MAS NMR) and C-13 (C-13 CP NMR) indicated that most of the Si-C bonds are unbroken during the synthesis process.

Hydrothermal synthesis and luminescent properties of LuBO3: Tb3+ microflowers

Hexagonal vaterite-type LuBO3:Tb3+ microflower-like phosphors have been successfully prepared by an efficient surfactant- and template-free hydrothermal process directly without further sintering treatment. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence(PL) and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples.

Nanoporous In2O3 nanocrystal clusters: One-step synthesis, thermal stability and optical property

Nanoporous In2O3 nanocrystal clusters with high surface areas have been synthesized by a one-step solvent-thermal method at a relatively low temperature. On the basis of our experimental data and nanomaterial growth mechanism, a template-assistant dehydration accompanied by aggregation mechanism was proposed to explain their formation. Besides, the influence of the high-temperature treatment on their porous structure and optical properties were studied and compared by various technologies.

Preparation and application of single polyelectrolyte microcapsules possessing tunable autofluorescent properties

Autofluorescent single polyelectrolyte microcapsules, exemplified by poly-L-lysine (PLL), have been prepared through glutaraldehyde-mediated covalent layer-by-layer (LbL) assembly and subsequent core removal. CaCO3 microparticles were used as template cores for the LbL deposition and removed by treatment of ethylenediamine tetraacetic acid disodium salt (EDTA). The prepared microcapsules, without conjugating an exterior fluorochrome, exhibited evenly distributed fluorescence.

Self-assembled 3D microflowery In(OH)(3) architecture and its conversion to In2O3

Using sodium dodecyl sulfate (SDS), a 3D microflowery indium hydroxide [In(OH)(3)] structure assembled from 2D nanoflakes was fabricated in a large quantity via a hydrothermal approach at relative low temperature. The obtained In(OH)(3) flowers exhibited a narrow size range between 4 and 6 mu m. The properties of these composites were characterized by XRD, EDX, FE-SEM, TEM, SAED, and TGA. In this work, both the use of urea and SDS and the amounts of these components played important roles in the formation of In(OH)3 with different nanostructures.

Nucleation and growth of CUSO4 center dot 5H(2)O crystals on the liquid state stearic acid Langmuir-Blodgett film

Oriented crystallization of CUSO4 center dot 5H(2)O on a Langmuir-Blodgett (LB) film of stearic acid has been studied in the temperature ranges of 73-68 degrees C and 53-20 degrees C, respectively. This is the first time that the LB film at temperature above its melting point has been served as a template to induce nucleation and growth of crystals. The experimental results demonstrated that the LB film in the liquid state has the ability of directing the nucleation and growth of crystals. Moreover, X-ray diffraction patterns of the as prepared crystals revealed that the orientation of the attached crystals on the LB film is affected by temperature greatly.

Control for oriented growth of large size KCl crystals by the competition between spontaneous and induced nucleation/growth on a Langmuir-Blodgett film

Langmuir-Blodgett (LB) film of stearic acid was used as template to induce the nucleation and growth of KCl crystals when the KCl solution was cooled from 50 to 25 degrees C. When the LB film template was vertically dipped into the solution, only induced crystals with (1 1 0) orientation were formed. However, if the template was horizontally placed into solutions, both the induced nuclei at the solution/film interface and spontaneous nuclei formed in solution were simultaneously absorbed onto the LB film, and then grew further to form crystals. X-ray diffraction (XRD) patterns and optical microscopy images showed that the orientation and morphology of the crystals were controlled properly by changing the orientation and position of the LB films in the solutions.

Palladium within ionic liquid functionalized mesoporous silica SBA-15 and its catalytic application in room-temperature Suzuki coupling reaction

Initially, pore walls of mesoporous silica SBA-15 with template were modified with chlorotrimethylsilane. Then imidazolium salts were similarly incorporated covalently in the inner pore walls of mesoporous silica SBA-15 albeit without the template. Finally, palladium salts were introduced into the pore channels of the previously processed mesoporous silica via electrostatic interaction. The resulting palladium catalysts demonstrated exceptional activity for the room-temperature Suzuki Coupling reaction in aqueous-organic mixed solvents and good recycling ability for at least 4-6 times.

Simultaneous synthesis of polyaniline nanotubules and gold nanoplates

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.

Preparation of ferrite MFe2O4 (M = Co, Ni) ribbons with nanoporous structure and their magnetic properties

Spinel ferrite, MFe2O4 (M = Co, Ni), ribbons with nanoporous structure were prepared by electrospinning combined with sol-gel technology. The ribbons were formed through the agglomeration of magnetic nanoparticles with PVP as the structure directing template. The length of the polycrystalline ribbons can reach millimeters, and the width of the ribbons can be tuned from several micrometers to several hundred nanometers by changing the concentration of precursor. The nanoporous structure was formed during the decomposition of PVP and inorganic salts.

Indium sulfide microflowers: Fabrication and optical properties

With the assistance of urea, uniform 2D nanoflakes assembled 3D In2S3 microflowers were synthesized via a facile hydrothermal method at relative low temperature. The properties of the as-obtained In2S3 flowers were characterized by various techniques. In this work, the utilization of urea and L-cysteine, as well as the amount of them played important roles in the formation of In2S3 with different nanostructures. Inferred from their morphology evolution, a urea induced precursor-decomposition associated with the Ostwald-ripening mechanism was proposed to interpret these hierarchical structure formation.

Facile synthesis and luminescence properties of octahedral YVO4:Eu3+ microcrystals

Uniform octahedral YVO4:Eu3+ microcrystals have been successfully prepared through a designed two-step hydrothermal conversion method. One-dimensional precursor Y4O(OH)(9)NO3 was first prepared through a simple hydrothermal process without using any surfactant, catalyst or template. Subsequently, well-defined octahedral YVO4 was synthesized at the expense of the precursor during a hydrothermal conversion process. XRD results demonstrate that the diffraction peaks of the final product can be well indexed to the pure tetragonal phase of YVO4.

Controllable Synthesis and Luminescence Properties of La(OH)(3) and La(OH)(3):Tb3+ Nanocrystals with Multiform Morphologies

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.