Synthesis of Mo-doped NiFe-phosphate hollow bird-nest architecture for efficient and stable seawater electrolysis

Abstract

Seawater electrolysis achieves sustainable hydrogen production and seawater desalination in the context of the scarcity of freshwater resources, achieving two birds with one stone. In this study, we reported an Mo-doped NiFe-phosphate hollow bird-nest architecture consisting of porous nanosheets on NiFe-foam (Mo-NiFe-PO3/NFF) as an admired bifunctional electrocatalyst for overall seawater splitting. The introduction of Mo distorted the crystal structure of NiFe-phosphate, regulated the electronic environment around the Ni/Fe, and improved the electrocatalytic activity. Moreover, it also cooperated with phosphate polyanions to resist the Cl− from seawater and enhanced the corrosion resistance. The Mo-NiFe-PO3/NFF exhibited outstanding electrocatalytic performance for alkaline seawater electrolysis under a two-electrode system where only required 1.65 V voltage to drive 100 mA cm−2. Particularly, the electrolyzer afforded industrially current density up to 500 mA cm−2 at a low voltage of 1.78 V, which were responsible for excellent durability up to 100 h. The bifunctional electrocatalyst in this study not only possessed high catalytic activity, but also effectively resisted the corrosion of Cl− in seawater.