Laser assisted solid state reaction for the synthesis of ZnS and CdS nanoparticles from metal xanthate

Abstract

Nanoparticles of CdS and ZnS were produced by a nanosecond laser using zinc (II) and cadmium (II) complexes of ethyl xanthate. Laser pulses with a peak wavelength of 355 nm, pulse repetition rate of 10 Hz, and pulse duration of 4 ns were used. The sample exposure time were 10 min and 30 min respectively. The obtained nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible spectroscopy (UV–vis) and photoluminescence (PL) spectroscopy. The morphology and optical property of the synthesized nanoparticles were investigated as a function of the time of exposure. Upon extensive irradiation, the crystallinity of the CdS nanoparticles increased while the crystallinity of the ZnS nanoparticles decreased. The average crystallite size of the CdS nanoparticles estimated from the TEM image was 4.8 nm, while the presence of aggregates with no crystalline edges impeded the size determination of the ZnS nanoparticles. The absorption spectra showed that the nanoparticles exhibit quantum confinement.