Preparation, Characterization and Photocatalytic Activities of TiO 2 ‐coated Activated Carbon Catalysts for Rhodamine B Photodegradation

TiO 2 ‐coated activated carbon ( TiO 2 / AC ) catalysts with high activity and easy separation were prepared by the coating method and their photocatalytic performances were studied for degradation of rhodamine B ( RhB ) dye. For this purpose, first, anatase TiO 2 nanocrystal was prepared via sol–gel process of titanium(IV) isopropoxide ( TTIP ), followed by reflux treatment at a relatively low temperature (130 °C) without further treatments. Second, four different amounts of AC were separately coated with TiO 2 by dipping in TiO 2 sol (10%, w/w) at room temperature. The catalysts were characterized by Fourier transform infrared ( FTIR ) spectroscopy, scanning electron microscopy ( SEM) , X‐ray diffraction ( XRD) , Brunauer–Emmett–Teller (BET) surface area, and UV –vis diffuse reflectance spectroscopy ( DRS ). Coating AC with TiO 2 produced catalysts with higher BET surface areas and greater crystallite sizes as compared to bare TiO 2 . RhB (50 mg/L) was almost completely discolored in 50 min, and the mineralization efficiency was 100% in 60 min for the catalysts containing 10 and 15% AC . Furthermore, all catalysts showed much higher photocatalytic activities than the commercial Degussa P‐25.