Engineering Ru nanoparticles embedded in 2D N-doped carbon nanosheets decorated with 2D Fe3O4–Fe3C heterostructures for efficient hydrogen evolution in alkaline and acidic media

Tailoring surface composition and structures of catalysts affects their catalytic performance in hydrogen evolution reaction owing to the geometric and electronic effects. Herein, Ru nanoparticles embedded in 2D N-doped carbon nanosheets decorated with 2D Fe3O4–Fe3C heterostructures (Ru/Fe3O4–Fe3C/NC) are fabricated via pyrolysis of the mixture containing 2D-Fe2O3 nanosheets, dopamine hydrochloride, RuCl3·xH2O, and melamine. Interestingly, the good hydrogen evolution behavior is achieved on Ru/Fe3O4–Fe3C/NC with the high reactivity and stability. Ru/Fe3O4–Fe3C/NC offers an overpotential of 141 mV to realize the current density of 10 mA/cm2 in 0.5 mol/L (M) H2SO4 electrolyte. As for 1 M KOH, Ru/Fe3O4–Fe3C/NC promotes hydrogen evolution reactivity with 148 mV to achieve 10 mA/cm2. The current density slightly degrades after continuous I-t tests, verifying the good stability for Ru/Fe3O4–Fe3C/NC. The high reactivity might stem from high dispersion of Ru nanoparticles, enhanced conductivity due to doping N into carbon nanosheets, and heterointerfaces between Fe–O and Fe–C.