Rational construction of cross-linked porous nickel arrays for efficient oxygen evolution reaction

It is important but challenging to design and fabricate an efficient and cost-effective electrocatalyst for the oxygen evolution reaction (OER). Herein, we report free-standing 3D nickel arrays with a cross-linked porous structure as interesting and high-performance electrocatalysts for OER via a facile one-step electrodeposition method. The 3D nickel arrays are strongly anchored on the substrate, forming self-supported electrocatalysts with reinforced structural stability and high electrical conductivity. Because of their increased active surface area, abundant channels for electron/ion transportation and enhanced electronic conductivity, the designed 3D nickel arrays exhibit superior electrocatalytic OER performance with a low overpotential (496 mV at 50 mA cm−2) and a small Tafel slope (43 mV dec−1) as well as long-term stability (no decay after 24 h) in alkaline solution. Our proposed rational design strategy may open up a new way to construct other advanced 3D porous materials for widespread application in electrocatalysis.