Electrochemically synthesized ordered TiO2 and platinum nanocomposite electrode: preparation, characterization, and...

Nanocomposite electrodes consisting of Pt and TiO2 nanotubular arrays have been synthesized, and the morphological, structural, and photoelectrochemical properties of the electrodes have been characterized by scanning electron microscopy, X-ray diffraction (XRD), and electrochemical methods. Highly ordered TiO2 nanotubular arrays can be obtained by anodizing titanium. The platinum nanoparticles are electrodeposited into TiO2 nanotubes by a chronopotentiometry method. Cyclic voltammetry and XRD measurements can confirm the presence of platinum in this nanocomposite electrode. This kind of nanostructural electrode greatly improved its performance for methanol oxidation under ultraviolet visible (UV-Vis) illumination compared to that without illumination. An enhancement of 58% in the current density has been observed upon illumination with UV-Vis light irradiance at an intensity of 50 mW/cm2. The improved performance of the TiO2/Pt nanocomposite electrode results from enhanced methanol oxidation by photo-generated holes in the TiO2 nanoarrays under illumination and a synergistic effect between TiO2 and Pt nanoparticles.