Nanoparticles of Pt loaded on a vertically aligned TiO2 nanotube bed: synthesis and evaluation of electrocatalytic activity

Abstract

A well distributed and uniformly covered Pt nano particle loaded TiO₂ nanotube (TiNT) electrode was synthesized via seed mediated hydrothermal reduction method on self-aligned TiNT bed obtained using electrochemical anodization of Ti foil in an organic electrolyte. The absence of a seeding step resulted in agglomeration of Pt nanoparticles on the TiO₂ nanotubes. Surface morphology and Pt nanoparticle loading were investigated using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The phase and chemical state of the synthesized electrode were examined by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electronic interaction between Pt nanoparticles and TiNT was also established by an XPS study. The electrochemical activity of the as-synthesized electrode was estimated for the electrooxidation of methanol and compared with that for Pt nanoparticles coated on Ti substrate and agglomerated Pt particle-coated TiNT. The corresponding results of this study confirmed that the Pt nanoparticle–substrate interaction and size of the nanoparticles have a definite role in enhancing the electrocatalytic activity.