Interfacial Engineering of Cofe-Ldh/Co-Mof Heteronanotube Arrays with Abundant Defects for Efficient Oxygen Evolution Reaction

Engineering the abundant phase interface is an effective strategy in enhancing the electrocatalytic activity of hybrid materials. Herein, CoFe-layered double hydroxide and Co-metal-organic framework (CoFe-LDH/Co-MOF) heteronanotube arrays are synthesized in situ via a straightforward three-step reaction process. The uniform hollow structure, substantial lattice defects and synergistic effects of CoFe-LDH and Co-MOF components, significantly promote the electronic and chemical structure of the heteronanotube arrays. Optimized heteronanotube arrays display exceptional performance in oxygen evolution reaction (OER) with ultralow overpotentials of 215 and 455 mV to deliver current densities of 10 mA cm−2 and 100 mA cm−2 with a small Tafel slope of 43 mV dec−1, and maintaining the electrocatalytic activity for a duration as long as 220 h, ranking it one of the top-performing MOF and non-noble-metal-based electrocatalysts for OER. Density functional theory calculations validate the reduction in free energy for the rate-determining step by the synergistic effect of Co-MOF and CoFe-LDH. This work establishes experimental and theoretical basis for promoting efficient water splitting through the design of heterostructures and the coupling of defects in catalysts.