Low-Temperature Preparation and Characterization of Nanocrystalline Anatase TiO₂

Abstract

Nanoanatase TiO2 of high crystallinity was prepared by a novel simple route at a temperature of 100 degrees C under mild conditions. Tetrabutyl titanate was used as a titanium precursor, Acetic acid was used as an inhibitor, and diethyl ether anhydrous was used as a solvent. X-ray powder diffraction (XRD), laser Raman spectroscopy (Raman), BET surface area analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and UV-vis diffuse reflectance spectra (DRS) were applied to characterize the crystallinity, morphology, surface structure, and other physicochemical properties of the nanoanatase TiO2. The photocatalytic activity of the prepared photocatalyst was evaluated by the photodegradation of formaldehyde in aqueous solution and compared with the commercial photocatalyst, namely, Degussa P-25. The result showed that the sample prepared at low temperature showed photocatalytic activity. The activity of the sample prepared at 120 degrees C was high and close to the sample calcined at 300 degrees C for 2 h. The degradation of formaldehyde by the highest active sample (calcined at 400 degrees C for 1 h) could almost achieve 100% within 80 min, which exhibited much higher photocatalytic activity than Degussa P-25

Nanocrystalline TiO2–diatomite composite catalysts: Effect of crystallization on the photocatalytic degradation of rhodamine B

“…Another peak of the adsorbed water is located at the wavenumber of 1634 cm −1 due to bending vibration of O H groups [21,22]. The appearance of a broad band in between 474 cm −1 and 796 cm −1 in case of diatomite-titania composite can be assigned to the characteristic stretching vibration of TiO 2 [5,23] indicating the deposition of TiO 2 layer on diatomite. The shifting of stretching vibration band due to O H group toward lower wavenumber also supports the formation of diatomite-titania composite where this shifting could be due to the replacement of adsorbed water molecules by the TiO 2 species [21].…”

Structural characterization of N-doped anatase–rutile mixed phase TiO2 nanorods assembled microspheres synthesized by simple sol–gel method

“…A relatively sharp peak observed at 1,625 cm -1 is associated to -OH bending mode of water on the surface of the TiO 2 [2]. Meanwhile, the absorption at 1,396 cm -1 is due to -C-H stretching vibration peaks corresponding to the presence of organic species contaminant on the surface from alkoxide precursor [2,17,18]. Moreover, the obvious peaks around 1,346 and 1,095 cm -1 in samples T75 and T400 are due to the presence of N 2 O 2 2-and NO -species [17,19].…”

“…The broad peak located at 3,100 cm -1 is due to the stretching of -OH groups. A relatively sharp peak observed at 1,625 cm -1 is associated to -OH bending mode of water on the surface of the TiO 2 [2]. Meanwhile, the absorption at 1,396 cm -1 is due to -C-H stretching vibration peaks corresponding to the presence of organic species contaminant on the surface from alkoxide precursor [2,17,18].…”

“…Titanium dioxide (TiO 2 ) is one of the semiconductors that have been widely used as a photocatalyst in water and wastewater treatment due to its chemical stability, low cost, excellent optical and electronic properties, as well as high photocatalytic activity [1,2]. Compared to rutile and brookite, anatase had shown the highest photocatalytic activity in the degradation of various organic pollutants in wastewater treatment.…”

“…Compared to rutile and brookite, anatase had shown the highest photocatalytic activity in the degradation of various organic pollutants in wastewater treatment. Most of the previous studies have focused on the preparation of single-phase TiO 2 nanostructures [1][2][3][4][5]. In addition, a recent study revealed that the combination of anatase-rutile mixed phase exhibited excellent photocatalytic activity compared to its single constituents [6][7][8][9][10].…”