Effect of Various Fuels on Structure and Photo-Catalytic Activity of Nano-Crystalline TiO2 Prepared by Microwave-Assisted Combustion Method

Nano-crystalline tio2 powders were synthesized by combustion method using metal nitrate solution and urea, glycine and citric acid fuels. microwave irradiation was used as the heating source. x-ray diffraction, scanning electron microscopy, fourier transform infrared spectroscopy and brunauer-emmett-teller surface area analysis were performed to characterize the prepared samples. x-ray diffraction patterns revealed that in the case of citric acid, calcination step is needed to obtain the desired phase. moreover, the ratio of rutile/anatase phases varied from 25/75 to 0/100 as the fuel type was changed from urea to glycine and citric acid. the crystallite size of the synthesized samples was calculated by scherrer’s formula which was revealed to be 8-15 nm. the highest surface area was observed when glycine fuel had been used. by scanning microscopy images, thick and thin flaky particles were detected in the case of citric acid and urea samples while a porous spongy morphology was seen when using glycine sample. the sample synthesized using urea is a better candidate for photo-catalytic functions due to a well-crystallized mixed crystalline structure (75% anatase - 25% rutile) which results in the synergistic effects of mixed anatase and rutile phases. prog. color colorants coat. 4(2011), 85-94. institute for color science and technology