Pt nanoparticles sputter-deposited on TiO2/MWCNT composites prepared by atomic layer deposition: Improved electrocatalytic activity towards the oxygen reduction reaction and durability in acid media

Acid-treated multi-walled carbon nanotubes (MWCNTs) were decorated with TiO2 using the atomic layer deposition (ALD) technique followed by uniform distribution of platinum nanoparticles (PtNPs) through magnetron sputtering. Surface analyses were performed by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical decontamination and characterization of the Pt-TiO2/MWCNT electrodes were carried out by CO stripping followed by cyclic voltammetry in acid media. The oxygen reduction reaction (ORR) was studied in O-2-saturated 0.05 M H2SO4 solution using the rotating disk electrode (RDE) method. Durability of the prepared catalysts was examined by repetitive potential cycling. Electrochemical data obtained was analyzed and compared to that of the commercial Pt/C catalyst. It was revealed that the Pt-TiO2/MWCNT catalysts possess higher ORR activity and better durability as compared to that of the commercial Pt/C. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.