Robust interfacial Ru-RuO2 heterostructures for highly efficient and ultrastable oxygen evolution reaction and overall water splitting in acidic media

It is essential but challenging to develop advanced electrocatalysts for oxygen evolution reaction (OER) under acidic conditions to break the activity-stability trade-off. In this work, through the controlled partial oxidation of Ru nanoparticles embedded in amorphous carbon, a robust Ru-RuO2 heterostructure with electronic cooperative interfaces was rationally designed and cleverly constructed. The rich heterogeneous interface between Ru and RuO2 creates a good electronic synergy and achieves high-performance OER electrocatalysis in acidic media. The best Ru-RuO2-NC heterostructure exhibits exceptionally excellent activity with an ultralow overpotential (η10) of 176 mV, a high specific mass activity of 1.37 A mgRu−1 (Jm@1.53 V), and an outstanding long-term durability over 80 h at 10 mA cm−2 in acidic environment. More importantly, the Ru-RuO2-NC heterostructure can further be utilized as a bifunctional electrocatalyst to drive acidic overall water splitting with a low cell voltage of 1.55 V and steady operation for at least 40 h at 10 mA cm2, which possesses potential for implementation in the proton exchange membrane water electrolysis.