A strong coupled 2D metal-organic framework and ternary layered double hydroxide hierarchical nanocomposite as an excellent electrocatalyst for the oxygen evolution reaction

Efficient and cost-effective electrocatalysts for the oxygen evolution reaction (OER) are of paramount importance for renewable energy conversion and storage. Here, we developed a facile approach for integrating two-dimensional (2D) zeolitic imidazolate framework-67 (ZIF-67) nanoarrays and CoNiAl ternary layered double hydroxide (CoNiAl-LDH) nanoplatelets onto three-dimensional (3D) nickel foam (NF) to form a 3D hierarchical ZIF-67/CoNiAl-LDH/NF electrocatalyst. Due to the unique 3D hierarchical architecture with increased electrochemical active surface area, multi-porous framework, and intimate interfacial coupling effect, the as-prepared ZIF-67/CoNiAl-LDH/NF electrocatalyst exhibits excellent electrocatalytic activity towards OER with a small overpotential of 303 mV at 10 mA cm−2 and Tafel slope around 88 mV dec−1, much lower than those of the reported nickel- or cobalt-based OER catalysts. Moreover, the ZIF-67/CoNiAl-LDH/NF electrocatalyst also shows excellent electrochemical durability, and the hierarchical structure is well maintained with no detectable activity decay after continuous testing at 10 mA cm−2 for 8 h. The present work provides a general strategy for the rational design and synthesis of multi-functional 3D hierarchical catalyst, which is expected to exhibit superior performance in a wide range of catalysis, especially in water electrolysis.