Carbon nanotube–titanium dioxide nanocomposite support for improved activity and stability of an iridium catalyst toward the oxygen evolution reaction. Issue 55 (15th December 2022) - Kim, Eom Ji
Abstract : To improve the electrocatalytic activity and stability of an iridium nanoparticle catalyst toward the oxygen evolution reaction, carbon nanotube and titanium dioxide nanocomposites (CNT@TiO2 ) are presented as a high-performance support. 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.