Preparation And Characterization Of Cadmium And Lead Sulfides Micro(Nano)-Structures

In this paper, CdS microspheres with hierarchical structures, spherical CdS/ZnS nanocomposites, star-shaped PbS dendrites, and flower-like structured CdS microspheres,were successfully prepared by a facile hydrothermal method. The morphology and properties of the products were characterized by means of SEM, XRD,PL and UV-Vis spectrometer,the growth mechanism was briefly discussed and experimental parameters were also studied.1. CdS microspheres with hierarchical structures were prepared by a facile hydrothermal method with sodium dodecylbenzenesulfonate (SDBS) as structure directing reagent. The morphology evolution of CdS microspheres was studied versus reaction time and temperature and SDBS concentration. Scanning electron microscopy (SEM) investigation indicated that CdS hierarchical microspheres were constructed with CdS nanosheets which were further built up with assembled CdS nanoparticles. The growth mechanism was briefly discussed. UV-vis spectrum showed an absorption at 445 nm and photoluminescence (PL) spectrum exhibited visible emissions at 498 and 573 nm for CdS hierarchical microspheres. Electrochemiluminescence (ECL) from CdS hierarchical microspheres and its first application to sensing H2O2 were studied. A linear relation between the ECL intensity and H2O2 concentration, I =0.5764+2.3793 c, is obtained with a detection limit of 1×10-8 mol·L-1. These hierarchical CdS microspheres may have potential application in fabricating sensors for chemical and biochemical analysis. 2. Spherical CdS/ZnS nanocomposites were prepared via a hydrothermal process with L-phenylalanine as surfactant. Scanning electron microscopy (SEM) investigation indicated that the CdS/ZnS nanocomposites with rough surface and diameters of about 0.8μm, were constructed with lots of little nanoparticles of 10-30 nm in diameter. UV-vis spectrum held a strong shoulder peak at 230 nm and a weak broad peak at about 280 nm. The effects of various experimental parameters on the morphology of the product were investigated and the growth mechanism was briefly discussed.3. Star-shaped PbS dendrites were prepared by reaction of Pb(Ac)2 and thiourea via a simple hydrothermal process with hexamethylene tetramine (HMT) as capping reagent. The influence of various experimental parameters, such as reactant concentration, pH value, and capping reagent, on the morphology of the product was investigated and the growth mechanism was briefly discussed. 3D flower-like structured CdS microspheres were prepared through a similar hydrothermal process, and the morphology and properties were characterized.