Gradation of Nanoparticle Size by Stokes' Law: A New Approach for Synthesis of CdS Nanoparticles

Abstract

The synthesis technique and its allied process parameters have a specific effect on the nucleation, growth-dominated microstructure and properties of nanostructure materials. The properties of semiconductor nanoparticles strongly depend on its size, shape, composition, crystallinity and structure. Recently, semiconductor nanoparticles have been extensively investigated and gained much interest due to their unique properties and applications in diverse areas of science and technology. A new controlled technique for synthesis of CdS nanopartlicles by means of kinetic approach using well-known Stokes' law for free body falling in quiescent and viscous fluid has been employed. Nanoparticles of cadmium sulfide (CdS) have been synthesized by simple controlled chemical method using IR radiation heating without using any capping agent and stirring. The desired concentration of aqueous solutions of cadmium chloride (CdCl₂.2H₂O) and thioacetamide (CH₃CSNH₂) were reacted in a controlled manner by IR radiation heating at the reaction area (top layer of reactants solution) of solution results the formation of CdS nanoparticles following Stokes' law. The as-synthesized nanoparticles were characterized by XRD, optical spectroscopy and SEM with EDX analysis.