The Preparation of SnO2 Powders Using Polyol Process and Its Gas Sensing Characteristics

This study examined the gas sensing characteristics of nanocrystailline SnO2 powders prepared using the polyol process. A homogeneous Sn-precursor was prepared by heating a diethylene glycol solution containing SnCl2 and Poly Vinyl Pyrrolidone (PVP) at 200 degrees C for 5 h, which was then converted to SnO2 powders by heat treatment at 600 degrees C for 3 h. The size of the primary particles and agglomerates were dependent on [SnCl2]/[PVP] and the use of a nucleating agent PtCl, In pure SnO2 form, the sensor prepared from the stock solution containing [SnCl2]/[PVP] = 1/0.6 showed selective detection to 200 ppm CH3COCH3 in the presence of C2H5OH, C3H8, and CO. The addition of 10 ppm PtCl4 significantly enhanced the responses to CH3COCH3 and C2H5OH. This was attributed to the decrease in particle size and agglomeration as well as to the catalytic effect of Pt.