Pt nanoparticles, approximately 5-8 nm in diameter, are distributed on TiO2 nanotube arrays (NTs) by photodeposition method, both inside and outside of the tubes, for electrocatalytic oxidation of ethanol. The vertically aligned TiO2 NTs provide a three-dimensional frame for supporting Pt nanoparticles. The morphology and electrocatalytic properties of the as-obtained catalysts are investigated by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope, X-ray photoelectron spectroscopy, cyclic voltammetry, linear scan voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The significant enhancement of the oxidation of ethanol is achieved due to the smaller size of the Pt nanoparticles distributed on TiO2 NTs with large specific surface area and easy transport of electrons, as well as the stronger synergistic interaction between TiO2 support and Pt nanoparticles. (C) 2013 The Electrochemical Society. All rights reserved.