Carbon nanotube-titanium dioxide nanocomposite support for improved activity and stability of an iridium catalyst toward the oxygen evolution reaction.

ABSTRACT: In order to improve the electrocatalytic activity and stability of an iridium (Ir) nanoparticle catalyst toward the oxygen evolution reaction (OER) in acidic electrolyte, carbon nanotube and titanium dioxide nanocomposites (CNT@TiO₂) are presented as a high-performance support. TiO₂ was synthesized on CNTs by using a novel layer-by-layer solution coating method that mimics atomic layer deposition (ALD) but is cost-effective and scalable. In the nanocomposites, CNTs serve as the electron pathways and the surface TiO₂ layers protect CNTs from corrosion under the harsh OER conditions. Thus, CNT@TiO₂ demonstrates excellent corrosion resistance as well as a high electrical conductivity (1.6 ± 0.2 S cm^-1) comparable to that of Vulcan carbon (1.4 S cm^-1). The interaction between Ir and TiO₂ promotes the formation of Ir(iii) species, thereby enhancing the OER activity and stability of the Ir nanoparticle catalyst. Compared to commercial carbon-supported Ir (Ir/C) and Ir black catalysts, CNT@TiO₂-supported Ir exhibits superior OER activity and stability.

SUBMITTER: Kim EJ 

PROVIDER: S-EPMC9753482 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature