Abstract:

TiO₂/ACF composite was prepared by improved solgel method using Ti(OBu)₄ as titanium source. TiO₂ precursor was loaded on activated carbon fiber (ACF) by dip-coating method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and N₂ (77K) adsorption were used to characterize the obtained composite. High concentration gaseous benzene in a staticmode photocatalytic reactor was used as model compound for photocatalytic activity test. Gas chromatographmass spectrum (GC-MS) was used for intermediates identification. The results show that TiO₂ can form perfect thin film on ACF surface. With the increase of dipcoating times, surface area of TiO₂/ACF decrease, thickness of TiO₂ film increase, then split and even fall off. Complete anatase can be formed for the sample calcinated at 400℃ and phase transformation of anatase to rutile occurrs at 700℃. The crystal size of TiO₂ decrease with the increase of calcination temperature. The sample of TiO₂/ACF-400-2 calcinated at 400℃ and dip-coated twice exhibits the highest activity for benzene removal. Intermediate analysis result reveals that no toxic of phenol and quinine compound is detected.

Key words: titanium dioxide, activated carbon fiber, sol-gel, benzene, removal