Fabrication and Characterization of Pt/C-TiO_2 Nanotube Arrays as Anode Materials for Methanol Electrocatalytic Oxidation

摘要

A carbon-modified TiO_2 nanotube (C-TiO_2 NT) array is fabricated by depositing carbon in TiO_2 NTs, which are prepared by anodization of the Ti sheet. Well-dispersed Pt nanoparticles (NPs) are electrochemically deposited on the C-TiO_2 NTs. The performances of the as-prepared NT array electrode in the methanol oxidation reaction (MOR) as an anode are investigated. The results present in this study highlight such a finding: depositing partly graphitized carbon on the inside of TiO_2 NTs can significantly enhance the catalytic efficiency. An optimum forward oxidation peak current density (I_(pf)) of 71.6 mA cm~(-2) is obtained from the Pt/C-TiO_2 NT anode at a low Pt loading of 23 μg cm~(-2). The achieved I_(pf) is almost 27 times that achieved on Pt-modified TiO_2 NTs without carbon modification. The enhanced catalytic efficiency is mainly attributed to the superior electrical conductivity of the deposited carbon, which facilitates the well dispersion of Pt NPs, charge transfer during the MOR, and removal of the byproduct CO-like species.