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.