Search

Perpendicularly cross-bedded CuO microstructure has been prepared via a precursor-based route. First, Cu2(OH)3Br, as the precursor, was hydrothermally synthesized in 0.1 M hexadecyl trimethyl ammon...

Uniform 5 μm Bi2S3 microspheres and 8 μm microflowers were solvothermally synthesized in acetylacetone solution through thermolysis of the Bi3+-dithizone complex without any templates or surfactants. Bi2S3 microspheres composed of nanorods with a diameter of 20−40 nm were synthesized at 180 °C for 12 h. In similar conditions at 240 °C for 3 days, microflowers composed of nanowires with lengths up to several micrometers and diameter of 20−40 nm were obtained. Field-emission scanning electron microscopy (FESEM) showed in the initial stage in the formation process that smooth spherical cores were observed, then on the surface of the cores nanoparticles appeared, and finally nanorods or nanowires grew out and microspheres and microflowers formed. Electrochemical experiments using Bi2S3 in a lithium ion battery indicated that the first discharge capacity of Bi2S3 microflowers could reach about 148 mA h g−1.

A facile surfactant-assisted solvothermal method had been employed to selectively synthesize single-crystalline tellurium nanowires and nanotubes and realize the circular transformation of wirelike and tubelike nanostructures by means of tuning the reaction time. Nanowires with an average diameter of about 23 nm were fabricated after 16 h; however, the reaction time was elongated to 28 h, these nanowires transformed into needlelike nanotubes ranging from 15 to 45 μm in length and 250−320 nm in wall thickness with cuneiform groovelike nozzles. Surprisingly, as the time continued to 45 h, nanowires with diameters in the range of 10−20 nm were obtained finally. What's more, the influence of the amount of PVP, ethanol amine, and the reaction temperature on the crystal morphology and controlled synthesis had been studied systematically. Through the exact observation of time-dependent samples in the transformation process, a micellar template-based wire-self-assembly mechanism was proposed to illuminate the tra...

A solution-phase route has been developed for the synthesis of single-crystal CuO nanoribbons with widths of 10−80 nm, thicknesses of 5−20 nm, and lengths ranging from several hundred nanometers to several micrometers and for nanorings with diameters of 100−300 nm. The CuO nanoribbons and nanorings were fabricated by the reaction of CuCl2 and NaOH solutions with sodium dodecyl benzenesulfonate (SDBS). The as-synthesized products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), revealing that CuO nanoribbons and nanorings had single-crystal monoclinic structures and nanorings were closed but were not the simple superposition of two ends of the nanoribbons. On the basis of TEM observations, the formation processes of nanoribbons and nanorings can be interpreted by two stages: initial nanoflakes split into nanoribbons due to the Brownian movement of surfactant molecules, and then these nanoribbons that...

A novel polymer-assisted solution approach is designed for the synthesis of flexible Ag/C coaxial nanocables via one-step reduction and carbonization under hydrothermal conditions. In the process, ...

A solution-phase approach has been demonstrated for large-scale synthesis of selenium nanoneedles with the stem diameter ranging from 100 to 500 nm and lengths up to tens of micrometers, gradually becoming thinner to form a sharp tip, which were fabricated by reduction of Na2SeO3 with poly(vinyl alcohol) (PVA). An interesting feature of the nanoneedles is their tendency to form branches and junctions. The morphology, microstructure, and chemical compositions of the nanoneedles were characterized using various methods (XRD, XSP, FESEM, TEM, and high-resolution TEM), indicating that the nanoneedles were single crystalline with high purity, structurally uniform, and dislocation-free. On the basis of a series of TEM observations, the nucleation and growth process of selenium nanoneedles could be interpreted by a solid−solution−solid process and PVA-assisted formation mechanism: trigonal (t)-selenium sphere-like nanoparticles initially formed due to the incessant dissolution of the sphere-like amorphous (a)-s...