Electrocatalytic Activity of PtAu Nanoparticles Deposited on TiO2 Nanotubes

We report on a facile photoassisted approach to directly deposit PtAu nanoparticles (NPs) with controllable compositions on TiO2 nanotubes (TiO2NTs), which were synthesized by electrochemical anodization of Ti substrates. The fabricated TiO2NTs and TiO2-supported Pt and PtAu NPs were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The electrocatalytic activity of the TiO2NT supported, variably composed PtAu NPs was investigated by using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). Our studies have shown that TiO2NT-supported PtAu nanoparticles with the Au composition between 30 and 50% exhibit very high electrocatalytic activity toward formic acid oxidation and that the direct dehydrogenation is the dominant reaction pathway in the electrochemical oxidation process.