This article describes a facile L-cysteine-assisted solvothermal method in a mixed solution made of ethylenediamine (en) and distilled water for the large-scale synthesis of various PbS 1D and 3D novel nanostructures. By varying process parameters such as the molar ratio of Pb(OAc) 2 to L-cysteine (reactants), the volume ratio of water to ethylenediamine, and the reaction temperature, a variety of 3D architectural structures and a 1D wirelike structure can be controllably synthesized in large quantities. On the basis of early arrested growth (nanowires), a reasonable possible mechanism for the growth of PbS dendritic structures has been proposed. The as-prepared PbS products were examined using diverse techniques including X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffraction, high-resolution TEM, Raman spectroscopy, and photoluminescence emission.

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.

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A novel tetraethylenepentamine (TEPA)-directed method has been successfully developed for the controlled synthesis of ZnSe particles with distinctive morphologies, including nanobelts, nanowires, and hierarchically solid/hollow spheres. These structures, self-assembled from nanobelts and nanorods, have been synthesized by adjusting the reaction parameters, such as the solvent composition, reaction temperature, and the aging time. Results reveal that the volume ratio of H2O and TEPA plays a crucial role in the final morphology of ZnSe products. The mechanisms of phase formation and morphology control of ZnSe particles are proposed and discussed in detail. The products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), selected area electron diffraction, high-resolution TEM, Raman spectra and luminescence spectroscopy. The as-prepared ZnSe nanoparticles display shape- and size-dependent photoluminescent optical properties. This is the first time to report preparation of complex hollow structures of ZnSe crystals with hierarchy through a simple solution-based route. This synthetic route is designed to exploit a new H2O/TEPA/N2H4H2O system possibly for the preparation of other semiconductor nanomaterials.

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