Enabling the full exposure of Fe2P@NixP heterostructures in tree-branch-like nanoarrays for promoted urea electrolysis at high current densities

[Display omitted] •The tree-branch-like Fe2P@NixP/NF nanoarrays architecture was constructed.•Simultaneousenhancementoftheelectronandmasstransportcanberealized.•The Fe2P@NixP/NF electrode exhibits superior electrocatalytic HER and UOR activity. It’s highly desirable but still challenging, through the structure construction strategy, to design brilliant bifunctional electrocatalysts for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) with both fast electron and mass transport, especially under high current densities. Herein, a novel tree-branch-like Fe2P@NixP heterostructure nanoarrays on NF (denoted as Fe2P@NixP/NF) were fabricated as bifunctional catalysts to realize urea-rich-water electrolysis at large current density. Benefiting from the tree-branch-like hierarchical architectures with rich exposed heterointerfaces between Fe2P and NixP that can simultaneously achieve facilitated mass and electron transfer, the elaborated Fe2P@NixP/NF electrode shows brilliant electrocatalytic UOR and HER performance. The assembled Fe2P@NixP/NF|| Fe2P@NixP/NF couple could yield the current density of as high as 500 mA cm−2 at super low cell voltage of 1.604 V for urea electrolysis. We believe our work can chart a brand-new-path in developing an industrial electrolyzer to promise an energy-saving H2 generation along with urea-rich wastewater treatment.