Platinum/titania nanotube arrays as electrocatalysts for borohydride oxidation

Dijana Šimkūnaitė; Loreta Tamašauskaitė-Tamašiūnaitė; Aldona Balčiūnaitė; Aušrinė Zabielaitė; Sigitas Jankauskas; Algirdas Selskis

doi:10.6001/chemija.2017.28.4.5

Dijana Šimkūnaitė
Loreta Tamašauskaitė-Tamašiūnaitė
Aldona Balčiūnaitė
Aušrinė Zabielaitė
Sigitas Jankauskas
Algirdas Selskis

DOI: https://doi.org/10.6001/chemija.2017.28.4.5

Keywords: platinum, titania nanotubes, sodium borohydride, oxidation

Abstract

This work is focused on the study of Pt nanoparticles coated self-ordered titania nanotube arrayed electrodes (denoted as Pt/TiO2-NTs) as efficient platinum/titania nanotubes electrocatalysts for the oxidation of sodium borohydride in an alkaline medium. The Pt/TiO2-NTs catalysts with different Pt loadings were fabricated on the titania nanotubes arrayed surface via a facile electrochemical deposition technique. The surface morphology and composition of the Pt/TiO2-NTs catalysts were investigated using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The electrochemical behaviour of the prepared catalysts was examined towards the oxidation of BH4– ions in an alkaline medium by means of cyclic voltammetry. It has been determined that the electrocatalytic activity of Pt/TiO2-NTs catalysts towards the oxidation of BH4– ions depends on the Pt loading in the catalysts and is higher as compared with that of a smooth Pt electrode. It has been found that the Pt/TiO2-NTs catalyst with a Pt loading of 16.3 μgPt cm–2 and with deposited Pt nanoparticles ranging from several to 50 nm in size exhibited the highest specific and mass activities for the oxidation reaction of sodium borohydride.