Chemical deposition and electrocatalytic activity of platinum nanoparticles supported on TiO₂ nanotubes

Platinum electrocatalysts (Pt-B/TON-N₂, Pt-B/TON-air and Pt-H/TON-air) incorporated on annealed titaniumoxide nanotubes (TON_s) have been successfully synthesized by chemical deposition method using sodium borohydride and hydrazine, reducing agents. TONs were firstly prepared by anodization of pure Ti foil in HF solution followed byannealing in air andN2 atmosphere. The morphology and structure of the electrocatalysts were characterized by scanning (SEM), transmission (TEM) electron microscopies, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and electrochemical techniques. SEM, TEM, XRD and EDX characterization indicate the presence of platinum nanoparticles with diameter less than 50 nm and uniformly incorporated into TON arrays. The electrocatalytic activities results show that the Pt-B/TON-N₂ catalyst has higher catalytic activity for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) comparedwith Pt-B/TON-air and electrodes prepared using hydrazine as reducing agent because the better conductivity. In addition, the Pt-B/TON-N₂ catalyst exhibits better poison tolerance and two times higher methanol oxidation current density thanthat reported for Pt/carbon catalyst. This suggests that the Pt-B/TON-N₂ catalyst supported on TON-N₂ has promising potential applications in electrocatalyst reactions.