Abstract: | Although numerous ruthenium‐based phosphates possess high catalytic activities for hydrogen evolution reaction (HER), most of them rely on dangerous and toxic synthesis routes. Biological slices confirm that Ru ions can penetrate the cell walls of saccharomycete, which facilitates the adsorption of Ru ions. Herein, based on a green synthesis process by saccharomycete cells as the carbon template and nitrogen/phosphorus (N/P) sources, novel Janus‐like ruthenium–ruthenium phosphide nanoparticles embedded into a N/P dual‐doped carbon matrix (Ru–Ru2PΦNPC) electrocatalyst for HER are synthesized. Electrochemical tests reveal that Ru–Ru2PΦNPC displays remarkable performance with a low overpotential of 42 mV at 10 mA cm?2 and demonstrates superior stability at a high current density in 0.5 m H2SO4. Furthermore, ruthenium oxide nanoparticles coated N/P dual‐doped carbon (NPC@RuO2) are also synthesized with a yolk–shell structure using saccharomycete cells as the core template and RuO2 as a shell to isolate saccharomycete cells from the oxidation reaction during calcination in air. The NPC@RuO2 as oxygen evolution reaction electrocatalyst possesses a low overpotential of 220 mV at 10 mA cm?2. Finally, the Ru–Ru2PΦNPC is integrated as a cathode and NPC@RuO2 is integrated as an anode to construct a two‐electrode electrolyzer to enable an excellent performance for overall water splitting with a cell voltage of 1.50 V at 10 mA cm?2 in 0.5 m H2SO4. |