Gas sensing property and microstructure of SnO2 nanocrystalline prepared by solid state reaction—thermal oxidation

Nanocrystalline SnO2 powders have been synthesized by two-step solid state reaction technique. Firstly, the brown SnO particles were obtained by grinding mixed SnCl2·2H2O and KOH powders at room temperature. Then, the powders were calcined in air (thermal oxidation) to form the SnO2 nanoparticles. The phase compositions and microstructures of the product were examined by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), respectively. Furthermore, we have measured the gas-sensing property of the products and found its distinct selectivity towards ethanol at the presence of gasoline and acetylene, which is different from the property of pure SnO2 nanoparticles. The mechanism of such a specificity was discussed briefly.