A novel Ir–Ru-based nanoparticle supported on ordered electrochemically synthesized TiO2-nanotube as a highly active and stable oxygen evolution reaction catalyst for water splitting in acidic media

Herein Iridium-Ruthenium-based OER electrocatalysts (Ir: Ru 60:40 at%) supported on electrochemically synthesized TiO2 nanotubes (IrRuOx/TNTs) at 80 wt% have been synthesized by the modified Adams fusion method. Physical and electrochemical characterization of the catalysts is compared with IrRuOx, 80 wt% IrRuOx/TiO2 and commercial RuO2. The total charge and the average diameter of the unsupported IrRuOx are 1655.0 mC mg−1 and 4.98 nm, respectively. The total charge and the average diameter for the IrRuOx/TNT have been obtained at 3647.5 mC mg−1 and 3.77 nm, respectively. IrRuOx/TNT shows a current density of 1000 mA mg−1 at 1.604 VRHE and a Tafel slope of 68.9 mV dec−1. Various methods, such as CV, CP, and CA, have been used to evaluate the stability of the catalysts. The results demonstrate that IrRuOx/TNT is a stable catalyst for use in harsh acidic OER environments and can exhibit good activity in a low noble metal loading.