Hierarchical Design of NiOOH@Amorphous Ni–P Bilayer on a 3D Mesh Substrate for High-Efficiency Oxygen Evolution Reaction

Recently, 3d metal phosphide and metal-phosphorus alloy have been intensively studied for the oxygen evolution reaction (OER). Research work has indicated that the presence of phosphorus could lead to the formation of a phosphide/(hydro)-oxide core/shell structure. In this work, we have developed a fabrication technique for a robust NiOOH@amorphous Ni–P bilayer on a zirconia mesh support through the collaboration of electroless deposition and robocasting. During the electroless deposition, a fully amorphous structure can be obtained with a certain phosphorus content (7–8 wt %). Relatively thick films (in the order of 5 μm) had an excellent adhesion on the mesh structure because of the large curvature. A stable Ni oxy/hydroxide surface (∼200 nm) can be formed in bilayer nature (NiOOH/Ni–P) due to preactivation. The combination of catalyst active sites on the surface and high conductivity of metallic body enables good OER performance with an overpotential of 286 mV at a current density of 10 mA cm–2. Together with excellent chemical stability and mechanical strength of the ceramic substrate, this novel combination gives rather excellent adhesion and stability in alkaline solution and provides a different angle for the hierarchical design of corrosion resistant and high-performance OER electrodes for industry.