Self-supported transition-metal-based electrocatalysts on iron foam for water splitting

Abstract

Electrocatalytic water splitting, as a highly promising pathway for clean hydrogen production, fundamentally relies on the construction of high-performance, cost-effective, and durable electrocatalysts. Compared to conventional powdered catalysts, self-supported electrodes exhibit significant advantages in simplifying electrode preparation processes, reducing interfacial resistance, enhancing active site exposure, and improving structural stability. Nevertheless, current self-supported electrocatalysts still face critical challenges. Firstly, the persistent bubble evolution under industrial-current–density induces localized stress concentrations and mechanical degradation, resulting in a marked compromise in the long-term operational stability of electrocatalyst; secondly, the dynamic surface reconstruction mechanisms of catalytic active species and their interfacial interactions with substrate materials during electrocatalytic water splitting remain insufficiently investigated at a systematic level. This review systematically summarizes recent advances in iron foam-based self-supported electrocatalysts, encompassing diverse material types including metal oxides, (oxy)hydroxides, sulfides, phosphides, nitrides, and metal–organic frameworks. By establishing a “synthesis strategy-structure-performance” relationship framework, we comprehensively analyze enhancement mechanisms of activation strategies on the reaction kinetics of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), such as morphology engineering, heteroatom doping, multicomponent heterostructures, and defect engineering. Finally, we provide future prospects of developing iron foam-based self-supported electrocatalysts from material design and engineering application. This work advances the mechanistic understanding of iron foam-supported catalysts for water splitting while providing theoretical frameworks for the rational design of high-performance catalyst.