A novel magnetically separable composite photocatalyst: Titania-coated magnetic activated carbon

A novel magnetically separable composite photocatalyst, titania-coated gamma-Fe2O3 magnetic activated carbon, was prepared by depositing of anatase titania onto the surface of magnetic activated carbon (MAC) which was prepared by a simple route: directly adsorbing of magnetic gamma-Fe2O3 nanoparticles onto activated carbon (AC). The prepared samples were characterized by XRD, SEM, BET and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples was determined by degradation of model contaminant water of phenol aqueous solution, and compared to Degussa P25. The effect of gamma-Fe2O3/AC mass ratio on the photocatalytic activity was also studied. Results illustrated that photocatalyst with gamma-Fe2O3/AC mass ratio of 1:7 showed the highest degradation rate, which was nearly twice to that of P25. The photocatalyst can be separated easily by an external magnetic field. It can also be re-dispersed into aqueous solution by stirring after the removing of external magnetic field. The photocatalyst can be recycled with a little decreasing of photocatalytic activity, and the degradation rate of phenol was still higher than 80% after six cycles. (c) 2007 Elsevier B.V. All rights reserved.