Influence of Temperature on TiO2 Nanoparticles

TiO2 nanocrystalline powders were synthesized in the anatase phase by a modified sol-gel method. The effect of calcination temperature was also studied; XRD pattern of the sample dried at 100°C showed a significant amount of amorphous content, and crystallinity enhanced by increasing the calcination temperature. AFM images demonstrate submicron agglomerate particles. FT-IR spectra represent the formation of Ti-O-Ti bond for the as-prepared powder. Following the trend of increasing the temperature Ti-O bond was intensified. The pure anatase structure with no undesirable impurity phase was resulted at 500°C. N2 adsorption and desorption isotherms pointed out a mesoporous powder and the specific surface area using BET method was measured 50 m2/g, which is corresponding to about 30 nm particle size. This is in agreement with TEM and XRD results of particle average diameter. Photocatalytic activity of the sample calcined at 500°C was examined using methyl orange, which is comparable with commercial TiO2 (P-25). This method of nanopowder synthesis is presentable, since well-crystallized nanoparticles with good surface area and photocatalytic activity can be achieved.