Effect of Ce3+ and Pd2+ doping on coral-like nanostructured SnO2 as acetone gas sensor

SnO2 nanocrystals with coral-like porous structure were prepared with sol-gel method combining with an annealing process. The crystallite size and structure of SnO2 were characterized with X-ray diffraction and scanning electron microscope. The average coral-like nanostructrured SnO2 crystallite size is about 13 nm. The acetone gas sensors were obtained by sintering the mixture of coral-like porous nanostructured SnO2 and PdCl2, Ce(NO3)3 respectively. The acetone gas sensing properties of the mixed solid powder were measured by the commercial gas-sensing measurement system. Pd-doped sensors show decreased sensitivity to acetone, compared to that of the undoped sensor. On the other hand, the sensor based on 0.5 mol% Ce-doped shows the highest response to acetone at 190 degrees C. It exhibits a good linear relationship with the acetone concentration (10 - 1000 ppm) in logarithmic forms, which can provide potential applications for acetone detecting.