Synthesis of wide spectrum of mesoporous titania materials by forced co-hydrolysis of Zr–Ti alkoxides

• A wide spectrum of mesoporous and crystalline ZrO2 (5 mol%)-TiO2 products have been synthesized.
• A temperature higher than 110 °C needs for the crystallization of anatase.
• The mesopores size is a direct consequence of the crystal size of anatase.
• The catalyst and the alcoholic media affect the crystal size of anatase during the hydrolysis.

A wide spectrum of mesoporous titania (TiO2) materials has been synthesized by co-hydrolysis of titanium tetraethoxide in mixture with zirconium tetraisopropoxide (5 mol%) by changing the hydrolysis temperature, from 110 °C to 140 °C, the reaction time, from 20 h up to 144 h, the catalyst, NH4OH or NH4Cl, and the alcoholic media, ethanol or isopropanol. For short reaction times and/or for low temperatures of hydrolysis, micrometer aggregates of amorphous and microporous products were obtained. By increasing both the reaction time and temperature, the crystallization of TiO2-anatase occurs with a strong change of micropores into mesopores.In this work are discussed the numerous parameters which affect the crystallization of TiO2, allowing to obtain a wide spectrum of mesoporous materials characterized by crystal sizes and average pore diameters ranging between 9 nm and 38 nm and from 2.5 nm to 16 nm, respectively.

SEM micrographs of products catalyzed by NH4OH in the presence of ethanol at room temperature for 1 h (a), at room temperature for 3 h (b) and at 140 °C for 144 h (c).Figure optionsDownload as PowerPoint slide