Ashish Tiwaria, S A Khanb and R S Kherc
Polyphosphate capped ZnS nanoparticles have been successfully synthesized by simple aqueous method using thiourea as S2- source. X-ray diffraction (XRD) indicated that the ZnS nanoparticles were 1.38 nm in size with a zinc blende structure. Morphology of the prepared sample was characterized using a scanning electron microscope (SEM). Surface characterization of the nanocrystals has been done by FTIR spectroscopy and it was found that the nanoparticles were sterically stabilized by sodium hexametaphosphate. Absorption spectra have been obtained using UV-Vis spectrophotometer to find the optical band gap. Particle size was calculated by deriving an equation using effective mass approximation (EMA). The results indicated that varying the capping agent concentration could produce stable ZnS nanocrystals with the mean size varying between 3.0 and 4.3 nm.
