Microporous titanium dioxide thin films have been fabricated on titanium plates by the micro-plasma oxidation method with the electrolyte of H2SO4. The influence of Fe3+ ions addition in the electrolyte on the photocatalytic activities was investigated. The results reveal that titanium dioxide thin films produced with Fe3+ addition electrolyte exhibit higher photoactivity than pure electrolyte for the oxidation of rhodamine B. The removal of rhodamine B reaches 90% for 30 min when Fe3+ addition concentrate is 0.2 g/L. Experimental results of X-ray diffraction and atom force microscopy show that the increase in activity is related to change in the lattice parameters and cell volume. (c) 2005 Elsevier B.V. All rights reserved.