The metal doped TiO2 was prepared with Fe(III), Co(II), Ni(II), Cu(II), Ag(I), La (III), Nd(III), Ho(III), and Y(III) as doped catalysts. These catalysts were carried by ceramic foams to enhance their photocatalytic efficiency, which was later studied with methylene blue (MB) and Escherichia coil (E. coli) as targets. The results suggested that the photocatalytic activities of TiO2 were enhanced when ceramic foams were used as catalyst carriers and that the photocatalytic efficiency could also be significantly increased by the dopants, especially by Ag(I) and rare earth. In the bactericidal activity testing, the inhibitory effect of TiO2 on E. coil was enhanced significantly when ceramic foams were used as carriers. Ag(I) doped TiO2 showed the greatest inhibition on E. coil. As to the E. coli cells treated by Ag(I) doped TiO2, the observation with a Scanning Electronic Microscope (SEM) suggested that the cells could no longer maintain their morphology and the spheroplasts were formed after the treatment. (C) 2011 Elsevier B.V. All rights reserved.