Zn ions surface-doped TiO2 nanotubes were synthesized via an assembly process based on ligand exchange reaction and with additional thermal treatment. First the ligand exchange reaction between zinc acetylacetonate and hydroxide radicals on TiO2 surface, introduced the Zn ions onto the surface of TiO2 nanotubes. then the Zn(acac)(2) assembled TiO2 nanotubes were calcined at an optimal temperature (400degreesC) to eliminate the organic ligands. The as-prepared Zn ions surface-doped TiO2 nanotubes showed a further improvement on the photocatalysis activity for degradation of methyl orange in water. (C) 2004 Elsevier B.V. All rights reserved.