Preparation and Electrocatalytic Performance of a Nitrogen-Doped TiO ₂ -Based Self-Supported Electrode

Exploring electrocatalysts with high activity, high stability, and low Ir loading for oxygen evolution reaction (OER) is crucial for the large-scale application of proton exchange membrane water electrolysis (PEMWE). In this study, a self-supported electrode comprising a N-doped self-supported TiO2 nanotube arrays layer (N-TNTAs) on Ti mesh, with subsequent loading of IrO2 on the N-TNTAs, was designed to promote the OER kinetics and stability. The IrO2/N-TNTAs exhibits excellent catalytic stability and the highest mass-specific activity (431.2 A g–1 IrO2). Further analysis reveals that the deposition of TNTAs on the Ti substrate provided abundant active sites for the IrO2 catalyst electrochemical deposition. Additionally, the modulation of the electronic structure by N doping and high proportion of Ir3+ species in hydrated IrO2 significantly enhance the OER performance. The excellent mechanical properties of the substrate and the synergistic interaction between the substrate and IrO2 further contribute to improved stability. This innovative approach shows great promise for application in other electro-catalytic systems and offers valuable perspectives for the rational design of highly efficient catalyst electrode structures.