Effect of Heat Treatment on the Phase Transformation from SnS to Pure SnS2

Abstract

SnS2nanoparticles were prepared by heat treatment of SnS nanoparticles at 300 °C under N2atmosphere for 1hour. SnS nanoparticles have been synthesized by chemical precipitation method. As synthesized SnS nanoparticles, for determining the optimal temperature, were heated at various temperatures; 100, 150, 200, 250 and 300 °C N2atmosphere for 1hour. The products are characterized by X-ray diffraction (XRD) , ultraviolet visible (UV-vis) absorbance spectra and photoluminescence (PL). XRD and optical absorption studies show an increase in particle size with increasing heat treatment temperature from 100 to 200 °C . However, a large decrease in the nanoparticle size along with transforming from SnS to SnS2 is observed at 300 °C.In addition, the optical properties of al samples , including both UV-vis absorption and emission spectra showed a blue shift as the particles size decreased.