Abstract: Two kinds of carbon aerogel (CA), CA125 and CA500, with pore diameters of ~18 nm and > 50 nm, respectively, were used as supports to prepare TiO₂/CA photocatalysts with the CA content of 20%. X-ray diffraction, scanning electron microscopy and N₂ adsorption-desorption were used to characterize the crystal structure, morphology, and pore structures of the TiO₂/CA photocatalysts, respectively. The loaded TiO₂ was mainly anatase with a little amount of rutile, which was homogeneously dispersed on the CA support. The activity of TiO₂/CA125 was much higher than that of TiO₂/CA500 in the photodegradation of methyl orange. The photodegradation rate over TiO₂/CA is mainly influenced by the pore structure of the catalysts. The favorable adsorption and suitable confinement effect of mesopore structure are beneficial to the photodegradation of methyl orange. Therefore, TiO₂/CA125 with the large amount of mesopores displays the higher photocatalytic activity than TiO₂/CA500.

Key words: carbon aerogel, titania, confinement effect, photocatalysis, methyl orange, degradation