Electron-rich ruthenium encapsulated in nitrogen-doped carbon for efficient hydrogen evolution reaction over the whole pH

The development of a low-cost and high-stability catalyst with Platinum-like electrocatalytic performance is significant for the hydrogen evolution reaction (HER) from water electrolysis. Herein, ultrafine ruthenium nanoparticles encapsulated in Nitrogen(N)-doped carbon anchored on graphene sheets are fabricated and utilized as HER electrocatalysts. Characterization results verify that the strong interaction between the N-doped carbon shell and the Ru core leads to charge redistributions, promoting Ru in a more active electron-rich state. Therefore, the catalyst exhibits excellent activity over a wide pH range, which only needs 16, 23 and 72 mV to drive a current density of 10 mA cm^-2 in alkaline, acidic and neutral electrolytes, respectively. In addition, the N-doped carbon shell protects the Ru nanoparticles from aggregation and decomposition in the extreme electrolyte, contributing to the excellent stability.