Structural and morphological study of mechanochemically synthesized tin diselenide

Abstract

Mechanochemical synthesis of tin diselenide, SnSe₂, was performed by high-energy milling of tin and selenium powder in a planetary ball mill. The mechanosynthesized product was characterized by X-ray diffraction, ¹¹⁹Sn MAS NMR and ¹¹⁹Sn Mössbauer spectroscopy, which confirmed the presence of the hexagonal SnSe₂ phase after 100 min of milling. The size and morphology of tin diselenide particles were studied by specific surface area measurements, and transmission electron microscopy. The specific surface area of powders was found to increase with increasing time of mechanochemical synthesis. Electron diffraction revealed reflections that correspond to hexagonal SnSe₂ modification. TEM observations show that the mechanochemical preparation route results in the formation of nanosized thick barrel-shaped SnSe₂ platelets. SnSe₂ nanoparticles show good absorption in the visible region of the UV-Vis optical spectrum and they evidence direct and indirect types of transitions in the lattice.