The application of TiO2 has been extensively studied, because the TiO2 produces a photocatalytic reaction that decomposes harmful materials using sunlight energy. In this study, the immobilization of the TiO2 particle on a brass substrate was investigated using the composite coating method. As a result of evaluating the, surface morphology using a scanning electron microscope, it was found that the codeposited TiO2(anatase) [TiO2(A)] particles were exposed on the surface of the Ag or Cu-TiO2(A) particle composite coating films. The proportion of the TiO2(A) particle on the surface increased with increasing the codeposit volume ratio of the TiO2(A) particle. The photocatalytic activity of the Ag-TiO2(A) composite film was significantly better than that of the Cu-TiO2(A) composite film. The reason for this difference was attributed to the effect of Ag itself (in the dark) and the synergistic effect of Ag and TiO2(A) (under UV radiation). (C) 2006 The Electrochemical Society.