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

Abstract

• The tree-branch-like Fe 2 P@Ni x P/NF nanoarrays architecture was constructed. • Simultaneous enhancement of the electron and mass transport can be realized. • The Fe 2 P@Ni x P/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 Fe 2 P@Ni x P heterostructure nanoarrays on NF (denoted as Fe 2 P@Ni x P/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 Fe 2 P and Ni x P that can simultaneously achieve facilitated mass and electron transfer, the elaborated Fe 2 P@Ni x P/NF electrode shows brilliant electrocatalytic UOR and HER performance. The assembled Fe 2 P@Ni x P/NF|| Fe 2 P@Ni x P/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 H 2 generation along with urea-rich wastewater treatment.