Cadmium Sulfide Nanoparticles: Synthesis and Characterization

Cadmium sulfide (CdS) nanoparticles were synthesized by wet chemical coprecipitation method using cadmium chloride and sodium sulfide as cadmium and sulfur sources, respectively. Ascorbic acid was used as capping agent. XRD analysis showed that the particles were present in hexagonal phase. The average particle size, using Debye-Scherer's equation, was found to be temperature dependent, 3.1 nm at 20 °C and 3.4 nm at 45 °C. The synthesized CdS nanoparticles revealed considerable blue shift in absorption edge compare to to the bulk CdS. They exhibited quantum size effect and showed an increase in band gap with the decrease in particle size. The average particles sizes obtained from XRD, TEM and UV-visible spectroscopy were found to be in good agreement with each other in the range 3-5 nm.