CuO Nanorod Arrays Shelled with Amorphous NiFe Layered Double Hydroxide Film for Enhanced Electrocatalytic Water Oxidation Activity

Recently, extensive efforts have been focused on CuO materials as the non-noble metal electrocatalysts for the oxygen evolution reaction (OER). However, their catalytic efficiency is still far from meeting the need of practical large-scale water splitting because of poor electrical conductivity and limited exposed active sites. Herein, we report that amorphous NiFe layered double hydroxide film can be grown on CuO nanorod arrays supported on Cu foil (NiFe-LDH/CuO NRs/CF) to construct a core–shell heterostructure via a facile electrochemical deposition approach. The resulting core–shell heterostructure demonstrates excellent OER performance in 1 M KOH, only requiring a small overpotential of 290 mV to drive the current density of 50 mV cm–2 with a low Tafel slope of 60 mV dec–1, and maintaining a steady current density of 50 mA cm–2 for at least 35 h with negligible decline in catalytic activity, which is the best OER performance among reported CuO electrocatalysts to date. Remarkably, this catalytic performance is also superior to that of the state-of-the-art IrO2 catalyst. The prominent catalytic performance of NiFe-LDH/CuO NRs could be attributed to the synergistic effect between NiFe-LDH film and CuO NRs. As a result, our research indicates that the construction of amorphous heterostructures could be a promising strategy for development of efficient OER systems.