Preparation, Characterization and Photocatalytic Activities of TiO2-coated Activated Carbon Catalysts for Rhodamine B Photodegradation

TiO2 ‐coated activated carbon (TiO2 /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 TiO2 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 TiO2 by dipping in TiO2 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 TiO2 produced catalysts with higher BET surface areas and greater crystallite sizes as compared to bare TiO2 . 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.