Comparison of various organic stabilizers as capping agents for CdS nanoparticles synthesis

Abstract

Results of the studies on the preparation and characterization of CdS nanoparticles capped with various organic stabilizers are presented in this article. Solutions of Cadmium acetate and Sodium sulphide were taken as the precursors. CdS nanoparticles were synthesized in an aqueous medium with Mercaptopropionic acid (MPA) as the stabilizer and non-aqueous methods were used for the synthesis of Polyvinyl Pyrrolidone (PVP) and thiophenol-capped CdS nanoparticles. The synthesized CdS nanoparticles were characterized by the optical absorption and X-ray diffraction (XRD) studies. Particle sizes estimated from the band gap values using Effective Mass Approximation (EMA) agreed fairly well with those calculated from the XRD using Scherrer formula. The quantity and the concentration of the stabilizers needed for effective capping of the CdS nanoparticles were different in the three cases considered. Stability of the synthesized CdS nanoparticles was studied at different intervals of time for 10 days. A change in particle size was observed at lower stabilizer concentrations for the first few days. But at higher stabilizer concentrations there was no change in particle size with time.