Characterization and electrochemical properties of Pt nanoparticles deposited on titanium oxide nanofibers

Abstract

To overcome problems with carbon corrosion, titanium oxide nanofibers (TNFs) were investigated as alternative supports for the deposition of Pt nanoparticles. In this work, pristine or Nb-doped TNFs were prepared using an electrospinning technique. Pt nanoparticles were deposited on the selected TNFs using a microwave-assisted polyol method. Nb doping and heat treatment in reducing atmospheres significantly affected the fiber diameter, grain size, oxygen vacancies, and electrical conductivity of the TNFs. The incorporation of Nb into the TiO2 lattice inhibited grain growth and phase transition in an oxidizing atmosphere. However, heat treatment in a reducing atmosphere resulted in a significant increase in grain size. As a result of Nb doping associated with heat treatment at 800 °C in a reducing atmosphere, all the anatase phase was converted to the rutile phase. In addition, Ti4+ was reduced to Ti3+, and Nb5+ was reduced to Nb4+. These transformations could be the basis for high electrical conductivity. The electrochemical surface area (ECSA) of Pt/Nb-TNF800 was 48 m2/g. The durability of the ECSA of this material was much distinguished compared to that of a commercial Pt/C catalyst.