l-Cysteine-Assisted Tunable Synthesis of PbS of Various Morphologies

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.