Unique Electrochemical Catalytic Behavior of Pt Nanoparticles Deposited on TiO₂ Nanotubes

In this study, we have directly deposited Pt nanoparticles on TiO2 nanotubes (TiO2/Pt) using a facile photoassisted reduction method. The Pt nanoparticles deposited on the TiO2 nanotube arrays possess a large electrochemically active surface area and exhibit remarkable kinetic behaviors. The peaks for the oxide formation and reduction progressively decrease and eventually disappear completely after 800 cycles, whereas the integrated charge for hydrogen adsorption and desorption reaches a constant, ∼70% of the initial value. In addition, an S-shaped cyclic voltammogram observed for the methanol oxidation at the electrochemically treated TiO2/Pt electrode was dramatically different from the results obtained at a bulk Pt electrode. The self-refreshment functionality and anatomy of the reconstructed TiO2-supported Pt nanoparticles described in this study provide a new approach for improving the catalytic activity of Pt nanomaterials in renewable energy applications.