preparation and characterization of tio2 nanoparticles prepared by sol-gel method

In this study, tio2 nanoparticles have been synthesized by sol-gel method in which aqueous solutions of titanium isopropoxide and ethanol were used to prepare the titania sol. ctab and span 20 were used as the surfactant stabilizing agent. then, the effects of the different parameters such as phs, stirring times, surfactants and temperatures on tio2 nanoparticles were studied. the x-ray diffraction (xrd), fourier transforms infrared spectroscopy (ftir), and transmission electron microscopy (tem) analyses were used to characterize the samples. the observations revealed that the ph of 3.5 and 36 h stirring time could provide dispersion without agglomeration with rutile and anatase phases. however, at higher ph, the powder resulted in the formation of anatase phase. using ctab as a surfactant could modify the shape, size, and provide better distribution of tio2 nanoparticles compared with that of the span 20 as a surfactant. finally, the nanopowder was calcined at 450, 550 and 650 °c. it obviously showed that by increasing the temperature, the size of the nanoparticles increases to 30 nm which might be due to acceleration in the crystal growth of titanium dioxide at high calcination temperatures.