Synthesis and dispersion medium-dependent stability of cadmium sulfide nanoparticles

Abstract

Wurtzite CdS nanoparticles (NPs) synthesized by a facile polyol method at 220 °C without extra surfactant were investigated using X-ray diffraction (XRD), Raman spectroscopy, dynamic light scattering (DLS) and zeta potential techniques. XRD data confirms hexagonal crystal structure with P63mc space group and no impurity peaks. Presence of two distinct Raman modes further confirms their stoichiometric formation. Dispersion medium-dependent stability of the NPs studied using zeta potential (ζ) data in the pH range from 3 to 10.5 reveals that these NPs are highly stable above pH 6.49 in basic medium with highest ζ of -39.32 mV at pH 10.28 in de-ionized water (DIW), but unstable in toluene and ethanol as dispersing medium. HD distribution curve shows that the particles agglomerate more rapidly in toluene and ethanol in comparison with that in DIW. This information is expected to be useful for many applications like ceramics, batteries, biological labeling, as a pigment in paints, as photocatalyst in degradation of organic pollutants.