In-situ generated Ni-MOF/LDH heterostructures with abundant phase interfaces for enhanced oxygen evolution reaction

Engineering the abundant phase interface in hybrid materials for high electrocatalytic activity is an effective strategy to enhance the electrochemical performance. In this work, Ni-MOF/Ox-MOF is constructed through the “growth of MOF on MOF” strategy. Following with in-situ conformal transformation in alkaline solutions, Ni-MOF/LDH heterostructures are fabricated, which exhibit excellent water oxidation activity owing to the high surface area of Ni-MOF substrate and the well-tailored phase interfaces. In addition, the high stability of Ni-MOF/LDH is demonstrated in a Zn-air battery. In-situ Raman technique identifies that the Ni centers are the true active sites during water oxidation. DFT calculations demonstrate that the charge transfer and the conductivity at the Ni-MOF/LDH interfaces is highly enhanced. This work provides an efficient method of fabricating MOF/LDH heterostructures with optimized phase interfaces and offers new insights into OER.