Enhanced Electrocatalytic Activity of TiO2 Nanotubes Modified with Pt and Pd Nanoparticles: Electro-Oxidation of Dopamine, Uric Acid and Ascorbic Acid

TiO2 nanotubes electrode was fabricated by anodizing Ti sheets in Fcontained solution. The final modified electrode was then prepared by electrochemical pulse deposition of Pd and Pt nanoparticles onto the surface of tubes. The morphological characterization of the modified electrode suggested a uniform and regular tubular structure which was decorated by metal nanoparticles. The performance of the modified electrode was characterized by cyclic voltammetry and differential pulse voltammetry methods. The Pt-Pd-TiO2 NTs modified electrode represented a relatively high sensitivity towards detection of dopamine in 0.1 M phosphate buffer solution (pH 7.00) as base solution. Over a wide concentration range of 2.0×10−7 to 1.0×10−4 M dopamine, the electrooxidation peak currents of dopamine experienced two limits of linearity. However the sensitivity of the PdTiO2 NTs was not acceptable for detection of dopamine. Furthermore, the Pt-PdTiO2 NTs modified electrode was able to distinguish the oxidation response of dopamine, uric acid and ascorbic acid in mixture solution of different acidity.