Gas sensing behavior of nanostructured sensors based on tin oxide synthesized with different methods

Tin oxide, SnO2 nanomaterials fabricated by chemical precipitation (CP), sol–gel (SG), and dissolution pyrolysis (DP) are characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The gas sensing properties of tin oxide nanomaterials prepared by CP, SG and DP methods have been studied. The results show that tin oxide nanopowders produced from three above-mentioned methods have tetragonal rutile structure and the mean size of particles are less than 30 nm. The results obtained from SEM show that tin oxide thick films (produced from the synthesized nanopowders) coated onto alumina substrates have different morphology and tin oxide thick films fabricated through DP method has porous structure. By the results obtained from the gas sensing behavior, the gas sensor based on tin oxide prepared by DP method has high sensitivity, excellent selectivity, quick response and recovery behavior to gases investigated compared with those fabricated by the other two methods.