Gas Sensing Characteristics of SnO_2 Whiskers Prepared from SNC_2O_4

SnO_2 whiskers were prepared from the decomposition of whisker-like SnC_2O_4,which was precipitated by a reaction between an aqueous SnCl_2 and oxalic acid solution at high solution temperatures (80℃).After the decomposition of SnC_2O_4 at 450℃,SnO_2 whiskers containing both of rutile and metastable orthorhombic phases were obtained with the content of the orthorhombic phase decreasing with increasing heat-treatment temperature and time.The effect of orthorhombic phase upon CO gas sensitivity was investigated by measuring the evolution of the primary particle size and the CO sensitivity with repeating heat treatment at 450℃.The 50μg/g CO sensitivity increased with decreasing concentration of the orthorhombic phase despite particle coarsening,which suggests that the orthorhombic phase is detrimental to the CO gas sensitivity.

SnO2 whiskers were prepared from the decomposition of whisker-like SNC2O4, which was precipitated by a reaction between an aqueous SnC12 and oxalic acid solution at high solution temperatures （80℃）. After the decomposition of SNC2O4 at 450℃, SnO2 whiskers containing both of futile and metastable orthorhombic phases were obtained with the content of the orthorhombic phase decreasing with increasing heat-treatment temperature and time. The effect of orthorhombic phase upon CO gas sensitivity was investigated by measuring the evolution of the primary particle size and the CO sensitivity with repeating heat treatment at 450℃. The 50 μg/g CO sensitivity increased with decreasing concentration of the orthorhombic phase despite particle coarsening, which suggests that the orthorhombic phase is detrimental to the CO gas sensitivity.