Abstract
Tin oxide SnO2 nanoparticles have been synthesized using chemical co-precipitation and solvothermal methods. The structures and morphologies of SnO2 prepared using both routes were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier infrared absorption spectroscopy (FT-IR), UV-Vis Spectroscopy and BET specific surface area. The XRD patterns showed the presence of the tetragonal structure in the nanometric range and both crystallinity as well as crystal size increased with the increasing in temperature. The size of the produced tin dioxide nanoparticles was from 6.2 to 10.6 nm by solvothermal route while it was from 9.3 to 16.2 nm for nanoparticles by co-precipitation pathway. Furthermore, TEM results showed that the sizes of SnO2 particles in all powders were tetragonal like structure and the grain size was increased with temperature. FT-IR spectra revealed that intensity of the transverse optical mode of Sn-O stretching vibration was increased with the sintering temperature while the bending vibration of O-Sn-O showed a blue shift. The optical band gap was shifted to a lower energy with increasing temperature due to the improvement of the crystallinity and the value was varied from 2.9 to 4.25 eV. The specific surface area of the as-made SnO2 in comparison with such calcined samples decreased with increasing the calcination temperature due to the changes in the sample particle size and in the sample crystal phases.