LAUSR

Highly efficient, stable, and low-cost catalysts of electrochemical water splitting play a critical role in promoting the energy efficiency in the power-renewable industry related to hydrogen. Herein, the non-precious metal carbides composed of Fe3C and Mo2C supported by carbon nanoplates are successfully prepared and utilized as bifunctional electrocatalysts for overall water splitting. Spatially confined annealing of the polydopamine-coated metal precursors renders the unique structure containing the porous cubes isolated by carbon nanoplates encapsulated with Fe3C and Mo2C nanoparticles. The hybrid electrocatalyst with a hierarchical structure, large surface area, and abundant exposed active sites benefits the mass transport and more importantly the strong charge-transfer effect between the iron and molybdenum moieties. In a strong alkaline condition, the optimized Fe3C/Mo2C hybrid (with a Fe: Mo ratio of 1:2) requires the a low overpotential of 274 and 301 mV for the electrocatalytic oxygen evolution reaction at a current density of 10 and 100 mA cm-2, respectively, accompanied with a decent hydrogen evolution activity, demonstrated an efficient bifunctional electrocatalysis towards overall water splitting. This work enlightens the rational design of hybrid electrocatalysts with unique hierarchical and synergetic electronic structures.