Laser Induced Morphology Change in Copper Sulphide Nanoparticles.

Copper Sulphide nanoparticles (CuS₀) were synthesized by reacting copper acetate with thiourea in oil-in-water microemulsions under high temperature conditions (65˚C). The prepared nanostructures were characterized using UV-visible spectroscopy, SEM, TEM, Raman, EDAX for their size, morphology, behavior and structure. These copper sulphide nanoparticles stabilized with Pluronic F-127 were found to be spherical in shape possessing λ_max at 922nm. The average diameter of the nanoparticles determined by TEM was 18nm. The prepared particles showed broad absorption spectrum in NIR region. The prepared particles were irradiated by using laser of 808nm (NIR region) for 10min(CuS₁₀), 20min(CuS₂₀) and 30min(CuS₃₀) to investigate its effect on morphology and behavior. The changes had been studied by TEM, SEM, Raman and by observing the shifts in UV absorbance peaks. Upon exposure to laser radiation, the monodispersed nanoparticles were found to assemble like flowers, small rods and long extended rods. Photo thermal efficiency keeps on decreasing with irradiation time. The nanoparticles were found to be amorphous initially which became crystalline, upon irradiation with laser light after 30 min. The possible criteria or mechanism involved in the formation of different nanostructures has also been discussed.