Facile synthesis of Pt nanoparticles supported on anatase TiO₂ nanotubes with good photo-electrocatalysis performance for methanol

A simple, high-yield and rinsing-free method is used in this work to prepare Pt nanoparticles with a size of approximately 2 nm, which are successfully supported on free-standing TiO₂ nanotubes (TNTs) synthesized by a simple two-step anodization method with titanium metal foil. Field-emission scanning electron microscopy images indicate that in the case of 30 V for 90 min, the inner diameter of as-synthesized TNTs is 60-70 nm and the length is approximately 1.9 μm. Electrochemical experimental results clarify that the Pt/TNTs/C catalyst has higher electrochemically active specific surface areas and better catalytic activity toward methanol electro-oxidation compared with the Pt/C and Pt/TNTs catalysts. What's more important, catalytic activity of Pt/TNTs/C is drastically enhanced under light illumination, with the mass activity of 525.0 mA mg_Pt^-1, 1.47 times higher than that in the dark (357.4 mA mg_Pt^-1). The improved activity is mainly derived from the synergistic effects between the electro-catalysis on Pt nanoparticles and the photo-catalysis of TiO₂ nanotubes. In this work, the improved photo-electrocatalysis performance of the Pt/TNTs/C catalyst is further analyzed and the findings here are of significance in providing a new strategy to fabricate Pt-based photo-electro catalysts for the methanol oxidation reaction.