High surface area SnO2 nanoparticles: Synthesis and gas sensing properties

SnO2 nanoparticles with high surface area have been synthesized by a homogeneous precipitation ethanol-thermal method with CO(NH2)2 and SnCl4·5H2O as starting materials. FT-IR, XRD, BET and TEM have been employed to characterize the as-prepared samples. The results show that the homogeneous precipitation ethanol-thermal method can effectively restrain the agglomeration, by which the SnO2 powders obtained are well dispersed and less aggregated with a size of 8–9 nm and high-specific surface area over 200 m2 g−1. On the other hand, the SnO2 powders prepared via the single homogeneous precipitation method showed lower specific surface area of 55 m2 g−1. The results of gas sensing measurements show that the sensors fabricated by the SnO2 nanoparticles obtained by the homogeneous precipitation ethanol-thermal method exhibit excellent sensitivity behavior to methanol and ethanol gases at room temperature. When the concentration of ethanol is 80 ppm, the sensitivity is ca. 25, and the recovery time is less than 25 s at room temperature.