title: Shape-controlled synthesis of 3D and 1D structures of CdS in a binary solution with L-cysteine's assistance.
abstract: A facile L-cysteine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D CdS spherical nanostructures constructed from CdS nanorods (or nanopolypods) in a binary solution. By controlling reaction conditions such as the molar ratio between Cd(OAc)2 and L-cysteine and the volume ratio of the mixed solvents, the synthesis of various 3D architectural structures and 1D wirelike structures in large quantities can be controlled. This is the first reported case of the direct growth of novel 3D self-assemblies of CdS nanorods (or nanopolypods). The morphology, structure, and phase composition of the as-prepared CdS products were examined by using various techniques (X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), high-resolution TEM, and Raman spectroscopy). On the basis of the results from TEM studies and our analysis, we speculate that in the present synthesis the L-cysteine dominates nucleation growth and the ethylenediamine (en)-dominated, oriented-assembly process. Interestingly, the products obtained show a gradient evolution in color from light-yellow to dark-yellow, which implies that their intrinsic optical properties change, possibly due to variations in their special morphologies and structures. This facile solution-phase L-cysteine-assisted method could be extended for the controlled preparation of other metal chalcogenides nanostructures with complex morphologies.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors.forename: Shenglin
authors.initials: S
authors.lastname: Xiong
authors.forename: Baojuan
authors.initials: B
authors.lastname: Xi
authors.forename: Chengming
authors.initials: C
authors.lastname: Wang
authors.forename: Guifu
authors.initials: G
authors.lastname: Zou
authors.forename: Lifeng
authors.initials: L
authors.lastname: Fei
authors.forename: Weizhi
authors.initials: W
authors.lastname: Wang
authors.forename: Yitai
authors.initials: Y
authors.lastname: Qian
mesh_terms: D019187:Cadmium Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D049329:Nanostructures; D036103:Nanotechnology; D043942:Nanotubes
chemical_list: D019187:Cadmium Compounds; D003545:Cysteine