Gas-sensitive properties of nanometer-sized SnO2

Nanometer-sized SnO2 particles were prepared by a sol–gel method using inorganic salt as a precursor material. The investigated results indicate that well-crystallized nano-sized SnO2 with size around 15 nm was obtained at annealing temperature 600°C. The activation energy for the growth of nano-SnO2 was calculated to be 26.55 kJ mol−1 when the annealing temperature was higher than 500°C. The measurements also show that there is a peculiar resistance change as a function of temperature for nano-SnO2. It has relevance to the increase of surface adsorbed oxygen. The selective detection for C4H10 and petrol can be increased when ruthenium ion was doped in nano-SnO2 as a catalyst. The gas sensitivity to CO, CH4, H2, etc., can be increased when rhodium ion was doped in nano-SnO2 as a catalyst and the detection to the several reducing gas can be realized ranging in temperature from 260°C to 400°C.