Core–Shell NiO@Ni-P Hybrid Nanosheet Array for Synergistically Enhanced Oxygen Evolution Electrocatalysis: Experimental and Theoretical Insights

Graphical Take a Ni : NiO@Ni-P nanosheet arrays behave as efficient electrocatalyst benefiting from the synergistic effect between NiO and Ni-P. As a durable 3D catalytic electrode for oxygen evolution reaction, NiO@Ni-P/Ti exhibits a high activity achieving a geometrical catalytic current density of 10 mA cm −2 at an overpotential of 292 mV in 1.0 m KOH. Cost-effective and highly-efficient electrocatalysts for the oxygen evolution reaction are crucial for electrolytic hydrogen production. Here, we report core–shell NiO@Ni-P nanosheet arrays as a high-performance 3D catalyst for water oxidation electrocatalysis. Such nanoarrays demand overpotentials of 292 and 350 mV to drive geometrical catalytic current densities of 10 and 100 mA cm −2 , respectively, with an activity superior to its NiO and Ni-P counterparts. Notably, this catalyst also shows a high long-term electrochemical durability with a Faradaic efficiency of 98.1 %. Density functional theory calculation reveals that the superior activity benefits from the synergistic effect between NiO and Ni-P.