Electrochemically Synthesized Ordered TiO_2 and Platinum Nanocomposite Electrode: Preparation, Characterization, and Application to Photoelectrocatalytic Methanol Oxidation

摘要

Nanocomposite electrodes consisting of Pt and TiO{sub}2 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 TiO{sub}2 nanotubular arrays can be obtained by anodizing titanium. The platinum nanoparticles are electrodeposited into TiO{sub}2 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 methanoi 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/cm{sup}2. The improved performance of the TiO{sub}2/Pt nanocomposite electrode results from enhanced methanol oxidation by photo-generated holes in the TiO{sub}2 nano-arrays under illumination and a synergistic effect between TiO{sub}2 and Pt nanoparticles.