IrO2/Nb–TiO2 electrocatalyst for oxygen evolution reaction in acidic medium

A corrosion-resistant Nb0.05Ti0.95O2 material with high surface area was prepared by a sol–gel process. IrO2 nanoparticles (about 16–33 wt%) were successfully loaded on Nb0.05Ti0.95O2 powders as the electrocatalyst for oxygen evolution reaction (OER) in acidic medium. The IrO2/Nb0.05Ti0.95O2 catalyst with the IrO2 loading of 26 wt% exhibits the best mass normalized cyclic voltammetry charge and mass normalized activity among all the IrO2/Nb0.05Ti0.95O2 catalysts because IrO2 nanoparticles were uniformly supported on the surface of Nb0.05Ti0.95O2 providing conductive channels to reduce the grain boundary resistance. Due to the anchoring effect of carrier on the catalyst, the stability of the supported IrO2 was significantly improved as compared to the unsupported one. The IrO2/Nb0.05Ti0.95O2 catalyst with 26 wt% IrO2 loading demonstrates the best effectiveness of the OER activity and cost.