Perspective on recent advances in self-supported electrodes with hierarchical structures for efficient and durable...

Hydrogen, as a carbon-neutral energy carrier, holds significant promise for sustainable energy systems, yet its production remains dominated by carbon-intensive methods. Water electrolysis offers a green alternative, especially when coupled with renewable energy, but its efficiency and economic viability are hindered by high overpotentials and the limited durability of electrocatalysts. This review highlights recent advances in self-supported electrodes with hierarchical structures for efficient water electrolysis. Such electrodes integrate catalytic materials directly onto conductive substrates, eliminating binders and enhancing electron transfer, active site exposure, and mechanical stability. We systematically discuss the design principles of hierarchical structures based on 1D, 2D, and 3D frameworks, along with strategies for enhancing intrinsic activity (e.g., interface engineering, heteroatom doping, vacancy engineering) and mass transport (e.g., curvature effects, bubble management). Furthermore, we address challenges related to scalability, stability under industrial conditions, and integration into practical electrolyzer systems. Finally, we outline future directions for the development of high-performance, durable, and cost-effective hierarchical electrodes to advance the industrial implementation of water electrolysis for sustainable hydrogen production.