Preparation Of Carbon Nanotubes/Cadmium-sulfide And PEI/CdS Composite Materials And Their Optical Properties

Under normal temperature, cadmium sulphide quantum dots were formed on the carbon nanotubes surface by decomposed the thioacetamide in an alcohol-water solution which contained ethylenediamine and ammonium acetate. UV-VIS,FT-IR,XRD and TEM were applied to characterize the surface structure and optical properties of the hybrid heterostructures. The results showed that the cadimium sulphide nanoparticle has been in-situ encapsulated onto the surface of carbon nanotubes with wurtzite structure. The average size is15nm. The formation mechanism of the quantum dots are discussed, ethylenediamine and cadmium ions formed complexes in the solution could reduce the concentration of cadmium ion, and thioacetamide in alkaline solution can slow decomposition release sulfur ion, so to preparation grain size smaller cadmium sulfide nanoparticles After learn the photoluminescence properties, we found that cadmium sulphide quantum dots could enhance the PL of carbon nanotubes. This helps to study the distribution of the surface defects in carbon nanotubes.The water soluble CdS quantum dots which have uniform particle size distribution were synthesized in the presence of polyethyleneimine (PEI). Here the CdS QDs were evaluate as a luminescence probe for metal ions in aqueous solution. Experiment results showed that the fluorescence emission of CdS QDs was significantly quenched by Ag+、Pb2+and Hg2+, Tributyl phosphine and prepared quantum dots could act as a bicomponent fluorescent sensor, it can selective detect trace silver ions in aqueous solution, the detection limit can reach10-8mol/L...