One-pot synthesis and gas sensitivity of SnO 2 nanoparticles prepared using two Sn salts of SnCl 4 ·5H 2 O and SnCl 2 ·2H 2 O

SnO2 nanoparticles were successfully synthesized by a novel one-pot route using two various Sn salts of SnCl4·5H2O and SnCl2·2H2O as raw materials, respectively. The thermogravimetric-differential scanning calorimeter (TG-DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and gas sensitivity measurement were characterized to determine the influences of salt type and calcination temperature on the thermal effect, crystal structure, crystallite size and gas sensitivity of SnO2 nanoparticles. Results indicated that the two series of samples had different crystallization process, crystallite size and gas sensitivity changed with calcination temperature. SnCl4·5H2O helped to promote crystallization, but SnCl2·2H2O suppressed the crystallization and crystallite growth even at the same calcination temperature. SnO2 nanoparticles calcined at 500 °C using SnCl4·5H2O and 250 °C using SnCl2·2H2O displayed better gas sensitivity because of high crystallinity and small crystallite size, possibly decreasing the number of boundary defects which can cause electron recombination as well as providing more reaction cites, respectively.