Ultrahigh Electrode Performance of Low‐Loaded Iridium Jagged Nanotubes for Water Electrolysis Applications

Abstract Highly active Ir electrocatalysts based on ultralow loading for proton exchange membrane water electrolysis (PEMWE) applications are desirable to achieve gigawatt production levels. However, no clear direction has been developed yet to achieve that scale. Here, newly‐synthesized Ir‐based jagged nanotubes (J‐IrNTs) with the ultrahigh electrode performance of 10 A mg Ir −1 at 1.6 V in a PEMWE cell at Ir loadings as low as 0.05 mg Ir cm −2 are reported, outperforming previously reported Ir‐based electrocatalysts. The Ir‐JrNT also exhibits only marginal degradation in stability tests. Notably, the resulting electrode of Ir‐JrNT provides enhanced intrinsic catalytic activity and high surface area for efficient electrocatalysis, with hierarchical branching composed of interconnected multiscale channels and highly corrugated surface textures, for facile mass transport. The findings demonstrate that the jagged nanotubular structure is a promising approach for overcoming the limitations associated with Ir‐based electrocatalysts and developing sustainable advanced PEMWE.