Ruthenium-based electrocatalysts toward electrochemical water splitting

Ruthenium-based materials (Ru and RuO2) are promising electrocatalysts toward electrochemical water splitting (EWS) though there are still issues with them that needs to be resolved such as relatively strong adsorption strength of intermediates over Ru and oxidative dissolution of RuO2. In this article, an overview of the recent progress and challenges with Ru-based electrocatalysts for EWS is provided. Firstly, fundamentals of EWS are summarized from the aspects of reaction mechanisms and activity descriptors. Next, the typical methods of fabricating Ru-based catalysts are demonstrated mainly including hydrothermal/solvothermal syntheses, organic ligand-assisted syntheses, pyrolysis, acid etching, cation exchange methods and molten salt-assisted syntheses. We then focus on illustrating the enhancing strategies toward creating advanced Ru-based electrocatalysts by demonstrating the typical examples, which include alloying, doping, structure design, interface engineering, single-atom catalyst design, high-entropy alloy design, phase engineering and defecting engineering. In this section, the structure-property correlation is elucidated aiming to the design of more efficient Ru-based electrocatalysts for EWS. Finally, we conclude the review by addressing the challenges and prospects of electrochemical water splitting and the development of Ru-based catalysts.