Preparation and characterization of cdse-decorated multiwalled carbon nanotube composites

Composites of carboxylated multiwalled carbon nanotubes (c-MWNTs) and CdSe nanoparticles were prepared by the electrostatic interaction. CdSe nanoparticles were stabilized by 2-(dimethylamino)ethanethiol hydrochloride to develop positive charges on their surfaces in aqueous solution. The structural characteristics of these composites were analyzed using X-ray diffraction (XRD), and transmission electron microscopy (TEM). Ultraviolet/visible (UV/vis) spectra of c-MWNT-CdSe composites showed the characteristic bands at ∼250 nm. These results indicate that the energy state of c-MWNTs is significantly modified, which was caused by the homogeneous distribution of CdSe nanoparticles in c-MWNTs, and the bond formation between c-MWNTs and CdSe nanoparticles. The photoluminescence (PL) of CdSe nanoparticles in the composites was characterized in comparison with that of CdSe nanoparticles. PL of CdSe in c-MWNT-CdSe composites was collected at ∼568nm in solution, but disappeared in powder state.