Preparation and electrocatalytic activity of Pt/Ti nanostructured electrodes

Abstract

Pt/Ti nanostructured electrodes have been prepared first by the electrophoretic deposition of Pt nanoparticles (7.4 and 11.1 nm) on a Ti support in reverse micellar solutions of water/Aerosol OT/isooctane, followed by heat treatment in air at 400–600 °C. The crystal structures of the resultant electrodes were characterized by XRD, and their electrocatalytic activities were investigated by cyclic voltammetry in a mixed solution of 0.26 M HCOOH and 1.0 M HClO4. The effects of the heat-treatment temperature and the size of the Pt nanoparticles were examined. It was observed that the electrocatalytic activity of the resultant Pt/Ti electrode for the oxidation of HCOOH was much higher than that of a bulk Pt electrode. With increases in the heat-treatment temperature and size of the Pt nanoparticles, the electrocatalytic activity of the Pt/Ti electrode decreased due to sintering and the reduction of the specific surface area. According to the cyclic voltammetric and XRD analyses, it was suggested that the resultant Pt/Ti electrode had lower percentages of Pt(100) and Pt(111) planes but a higher percentage of Pt(110) planes than the bulk Pt electrode. As the heat-treatment temperature increased, both the percentages of Pt(100) and Pt(111) planes increased but the percentage of Pt(110) planes decreased.