Carbon‐Quantum‐Dots‐Loaded Ruthenium Nanoparticles as an Efficient Electrocatalyst for Hydrogen Production in Alkaline Media

Abstract Highly active, stable, and cheap Pt‐free catalysts for the hydrogen evolution reaction (HER) are facing increasing demand as a result of their potential use in future energy‐conversion systems. However, the development of HER electrocatalysts with Pt‐like or even superior activity, in particular ones that can function under alkaline conditions, remains a significant challenge. Here, the synthesis of a novel carbon‐loaded ruthenium nanoparticle electrocatalyst (Ru@CQDs) for the HER, using carbon quantum dots (CQDs), is reported. Electrochemical tests reveal that, even under extremely alkaline conditions (1 m KOH), the as‐formed Ru@CQDs exhibits excellent catalytic behavior with an onset overpotential of 0 mV, a Tafel slope of 47 mV decade −1 , and good durability. Most importantly, it only requires an overpotential of 10 mV to achieve the current density of 10 mA cm −2 . Such catalytic characteristics are superior to the current commercial Pt/C and most noble metals, non‐noble metals, and nonmetallic catalysts under basic conditions. These findings open a new field for the application of CQDs and add to the growing family of metal@CQDs with high HER performance.