Preparation and characterization of highly active mesoporous TiO2 photocatalysts by hydrothermal synthesis under weak acid conditions

Mesoporous TiO2 photocatalysts have been synthesized in acetic acid aqueous solutions by using the amphiphilic triblock copolymer (Pluronic P123) template. The prepared photocatalysts were characterized by means of X-ray diffraction, transmission electron microscopy and nitrogen adsorption/desorption analysis. The phase and structural qualities of the obtained mesoporous TiO2 have been improved by using hydrothermal treatment. The hydrolysis reaction of titanium sources has been controlled by using a low concentrated acetic acid aqueous solution used as both hydrolytic retardants and acid catalysts because of the strong chelating effect and acidity of acetic acid. The obtained mesoporous TiO2 exhibits uniform mesoporous structure with different mean pore sizes of up to 9.0 nm. The photocatalytic activity of the obtained photocatalysts was investigated, using dimethyl phthalate as a modal pollutant. Over 90% of dimethyl phthalate can be photocatalytically degraded within 2 h under UV irradiation in the presence of the obtained photocatalysts with a concentration of 2 g/L The calcination temperature is the most remarkable factor that can affect the ultimate photocatalytic activity of the prepared photocatalysts. (C) 2009 Elsevier Inc. All rights reserved.