Abstract
In the thesis, we aimed to synthesize tin oxide and indium tin oxide nanocrystals via non-aqueous sol-gel route and study the activity of these materials for carbon monoxide sensing. Different ligands were used to control the size of the nanocrystals, and indium tin oxide of varied tin/indium ratio were prepared with proper combination of metal precursors. The obtained materials were characterized by powder X-ray diffraction, transmission electron microscopy, inductively coupled plasma mass spectrometry. The results indicated that tin oxide nanocrystal were highly crystalline, and the size of tin oxide could be well controlled by the addition of pyridine or water. For indium tin oxide nanocrystals, the size increased, as the molar ratio of tin/indium ratio decreased, and the nanocrystals with tin/indium ratio lower than 5.67 caused phase transformation from rutile to cubic phase. Results of carbon monoxide sensing indicated that indium tin oxide nanocrystals with 25 % of indium showed better response at lower operating temperature than tin oxide nanocrystals. We proposed an equation based on the reaction mechanism and reaction kinetics to estimate the concentration of carbon monoxide, and the results confirmed fair accuracy of the method.