Facile method for the selective growth of rice like rutile TiO 2 from peroxotitanate gel and its photo-activity

Abstract

Selective growth of rice like rutile titanium dioxide by hydrothermal method using titanium peroxide gel as a titanium precursor is reported herewith. Influence of synthetic parameters such as reaction time, temperature and pH on the morphology of the resulting nanocrystals has been investigated. To accomplish the monodispersed rice like rutile TiO 2 particles, trifluoroacetic acid is used as a growth regulator. Trifluoroacetic acid plays dual role i.e. to adjust the pH and growth regulator. The crystallinity and crystal size of TiO 2 increases with treatment temperature and time. The pH value of reaction mixture is found to be important for controlling the size, shape and structure of TiO 2. Hydrothermal treatment of peroxotitanate gel gives anatase TiO 2 with spherical like granular morphology but acidic pH by addition of trifluoroacetic acid, favors rice like rutile phase. The TiO 2 obtained was characterized using various instrumental techniques. Accordingly, a possible growth mechanism for the crystallization TiO 2 has been proposed. Suitability of TiO 2 photocatalyst is tested for the degradation of phenol under UV light and the results were compared with standard Degussa P-25 TiO 2. Surprisingly, the rice like rutile TiO 2 exhibit higher photo-activity than P-25 TiO 2. © 2012 Elsevier B.V. All rights reserved.