Activation of inert copper for significantly enhanced hydrogen evolution behaviors by trace ruthenium doping

The application of metallic copper in hydrogen evolution reaction (HER) is severely restricted by its low intrinsic activity due to its surface properties that have large energy barriers for water dissociation and weak binding force to H* . Herein, we report an electronic structure engineering strategy to activate the inert Cu for significantly enhanced HER performance by trace doping of Ru (0.70 wt%). Experiments together with theoretical analysis reveal that the Ru dopants attract electrons from the Cu, resulting in the surface with lower energy barriers for the water dissociation process and optimized binding energy with H* . The synthesized Ru doped Cu only involved overpotentials of 33 and 34 mV to reach 10 mA cm^-2 in alkali and acid, respectively, together with excellent long-term stability. This work presents an electronic engineering pathway to adjust the electrocatalysis behaviors of metallic copper.