Metal-organic frameworks-derived Ru-doped Co2P/N-doped carbon composite nanosheet arrays as bifunctional electrocatalysts for hydrogen evolution and urea oxidation

Construction of hybrid water electrolysis systems by coupling the urea oxidation reaction (UOR) with the hydrogen evolution reaction (HER) can potentially increase the energy efficiency for H-2 production and remedy the environmental pollution of urea. In this work, we demonstrated the synthesis of a HER-UOR bifunctional self-supported composite electrode, composed of metal-organic framework-derived low-Ru-content-doped Co2P nanoparticles/N-doped carbon composite nanosheets supported on 3D Ni foam substrates (Ru-Co2P/N-C/NF). Benefiting from the synergism of compositional and structural merits, the resultant self-supported Ru-Co2P/N-C/NF composite exhibited excellent electrocatalytic performance for both HER and UOR. Remarkably, the two-electrode urea electrolysis system composed of the bifunctional Ru-Co2P/N-C/NF composite electrode as both the cathode and anode could achieve a current density of 100 mA cm(-2) with a voltage of 1.58 V in 1 M KOH containing 0.5 M urea.