Synthesis and Characterization of CdS Nanoparticles with Strong Electrolyte Behavior

The CdS nanoparticles whose structure is similar to a strong electrolyte were synthesized by the colloidal chemical method. The CdS nanoparticles with Cd2+-rich surface are capped by the electrically neutral ligand of 2,2′-bipyridine (bpy), and the counterion, BPh4-, is adsorbed around the particle as balance charge. The ω donation from 2,2′-bipyridine at 2-position to the Cd2+-rich surface of the CdS nanoparticles was characterized by X-ray photoelectron spectroscopy (XPS). These CdS nanoparticles can redisperse in pyridine (py) or DMF, and have high stability. The determination of electroconductivity and the electrophoresis deposition in dilute solution containing the CdS nanoparticles further prove the rationality of the above electrolyte structure of the CdS nanoparticles.