Size-controlled synthesis and characterization of quantum-size SnO2 nanocrystallites by a solvothermal route

By using ethylenediamine as both an alkali and ligand, quantum size SnO2 nanocrystallites were synthesized with a solvothermal route. The transmission electron micrographs (TEM) were employed to characterize the morphologies of the products. The crystal sizes of the as-synthesized SnO2 were ranged form 2.5 to 3.6 nm. The crystal structure and optical properties of the products were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, optical absorption spectra, photoluminescence and Raman spectra. Anisotropic growth of the SnO2 nanocrystallites was observed by altering the solvent from water to ethanol. The SnO2 nanocrystal showed apparent quantum confinement effects. Finally, the mechanism for the formation of quantum size SnO2 was also discussed.