Ruthenium-Based Electrocatalysts for Electrochemical Water Splitting: A Review of Fundamentals, Synthesis, and Enhancement Strategies
Ruthenium-based materials, including metallic Ru and RuO2, are promising electrocatalysts for electrochemical water splitting (EWS) due to their high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, their practical application is hindered by the relatively strong adsorption of reaction intermediates on Ru surfaces and the oxidative dissolution of RuO2 under operating conditions. This review provides a comprehensive overview of recent progress and challenges in Ru-based electrocatalysts for EWS. We first summarize the fundamentals of EWS, including reaction mechanisms and activity descriptors. Then, we detail typical synthesis methods such as hydrothermal/solvothermal syntheses, organic ligand-assisted syntheses, pyrolysis, acid etching, cation exchange, and molten salt-assisted syntheses. Subsequently, we focus on enhancement strategies, including alloying, doping, structure design, interface engineering, single-atom catalyst design, high-entropy alloy design, phase engineering, and defect engineering, with typical examples illustrating structure-property correlations. Finally, we address remaining challenges and future prospects for the development of efficient and durable Ru-based electrocatalysts for sustainable hydrogen production.