Photocatalytic activity of TiO2 coated porous silica beads on degradation of cumene hydroperoxide

Recently, due to an increasing global concern on environmental safety, titanium dioxide (TiO2) photocatalyst has been extensively researched for use as air and water pollution treatments. This study was initiative for producing an economically viable TiO2 photocatalyst material with recyclability for degradation of CHP contaminated wastewater. TiO2 P-25, a well-known photocatalyst, with a proper amount (15% w/w of CAC) was coated on porous silica beads (ECOLITE (R)) by granulation technique, using high calcium aluminate cement (CAC) as a binder (EC+CAC+15% w/w TiO2 P-25). The experiments revealed that high concentration CHP solutions were completely degraded by EC+CAC+15% w/w TiO2 P-25 within 5 and 7 hours. The recyclability of EC+CAC+15% w/w TiO2 P-25 was evaluated by investigation the degradation activity of freshly prepared CHP solution under UV light irradiation using the repetitive photocatalyst beads for 6 runs. HPLC analyses indicated that the CHP degradation was completed in the 1(st) run and down to over 90% in the 6(th) run. Hence, EC+CAC+15% w/w TiO2 P-25 showed a long durability and good recyclability for CHP degradation, resulted from the good adherence of hydration product layer of CAC for TiO2 particles as well as its large surface area that offered good adsorption for CHP.