Synthesis of Anisotropic Tin Monosulphide Nanoparticles Using Sn-Thiourea as a Single Molecular Precursor.

We report the synthesis of high quality tin sulphide nanoparticles from tetrathiourea tin(II) chloride complex as a single molecular precursor. Thiourea ligand was used in the preparation of the complex due to its low toxicity and thermal stability. The reaction conditions were changed (reaction time, reaction temperature and nature of surfactant) to obtain high quality SnS nanoparticles that varied in morphology and size. The metal to sulphur ratio (Sn:S::1:1) and purity were confirmed using energy dispersive X-ray analysis (EDX). Spherical and rod shapes were obtained with an average particle size of 92.79 nm, estimated from transmission electron microscopy (TEM) images. Highresolution electron microscopy and X-ray diffraction (XRD) analysis show that the as-synthesized SnS nanoparticles had a pure orthorhombic crystal phase, with lattice spacing of 3.27 and 0.32 nm, which were assigned to the (111) and (021) reflection planes. A strong quantum effect was evident from the far blue shifted optical direct and indirect band gaps of 1.77 and 1.52 eV, respectively.