Preparing titanium oxide with various morphologies

Titanium oxide powder was prepared by hydrolyzing titanium tetraisopropoxide (TTIP) in aqueous solutions at pH 2, using TMC and NP-204 as surfactants. The anatase phase was formed when the precipitants were dried at 373 K. When the calcination temperature was below 773 K, all the powders were crystalline in the anatase phase. The powders changed to the rutile phase when the calcination temperature exceeded 1173 K. The powder calcined at 673 K has spherical primary particles with diameters of approximately 8 nm. When the powders calcined at 673 K were heated in NaOH solutions of various concentrations at 423 K for 20 h, titanium oxide powders with different morphologies were obtained. After the powders were refluxed in 5 M NaOH solutions, flower-like titanium oxide particles were formed. Nanotubes of titanium oxide about 8 run in diameter and over 600 rim long were obtained when the powders were refluxed in 10 M NaOH solution. (C) 2003 Elsevier Science B.V. All rights reserved.