High‐Performance Hydrogen Evolution by Ru Single Atoms and Nitrided‐Ru Nanoparticles Implanted on N‐Doped Graphitic Sheet

The most efficient electrocatalyst for the hydrogen evolution reaction (HER) is a Pt‐based catalyst, but its high cost and nonperfect efficiency hinder wide‐ranging industrial/technological applications. Here, an electrocatalyst of both ruthenium (Ru) single atoms (SAs) and N‐doped‐graphitic(GN)‐shell‐covered nitrided‐Ru nanoparticles (NPs) (having a Ru‐Nx shell) embedded on melamine‐derived GN matrix {1: [Ru(SA)+Ru(NP)@RuNx@GN]/GN}, which exhibits superior HER activity in both acidic and basic media, is presented. In 0.5 m H2SO4/1 m KOH solutions, 1 shows diminutive “negative overpotentials” (−η = |η| = 10/7 mV at 10 mA cm−2, lowest ever) and high exchange current densities (4.70/1.96 mA cm−2). The remarkable HER performance is attributed to the near‐zero free energies for hydrogen adsorption/desorption on Ru(SAs) and the increased conductivity of melamine‐derived GN sheets by the presence of nitrided‐Ru(NPs). The nitridation process forming nitrided‐Ru(NPs), which are imperfectly covered by a GN shell, allows superb long‐term operation durability. The catalyst splits water into molecular oxygen and hydrogen at 1.50/1.40 V (in 0.1 m HClO4/1 m KOH), demonstrating its potential as a ready‐to‐use, highly effective energy device for industrial applications. The successful fabrication of a catalyst comprised of Ru single atoms (RuSAs) and nitrided‐Ru nanoparticles (NPs) implanted on N‐doped graphitic sheet for hydrogen evolution reaction (HER) is demonstrated in this work. The near‐zero free energies for hydrogen adsorption/desorption on RuSAs and high conductivity of nitrided‐Ru(NPs) induce the HER activity, which provides realistic solutions for highly effective energy devices for industrial applications.