CuxO nanorod arrays shelled with CoNi layered double hydroxide nanosheets for enhanced oxygen evolution reaction under alkaline conditions.

[Display omitted] Exploration of highly efficient and cost-effective oxygen evolution reaction (OER) electrocatalysts is of crucial importance for the development of water splitting. In recent years, Cu-based materials have been widely concerned in OER due to their non-toxicity, rich reserves and highest reversibility. Meanwhile, Cu x O nanorods is easy to be prepared in industry. Herein, we report a fast preparation method to construct an integrated Cu x O@CoNi-LDH electrocatalyst with a unique 1D nanowire-2D nanosheet hierarchical core–shell structure by electrodepositing CoNi-LDH nanosheet arrays directly onto Cu x O nanorods (Cu x O were in situ-created on the Cu foam) at a large deposition voltage of −3.0 V vs SCE. The unique heterogeneous core–shell nanostructure, large deposition amount of CoNi-LDH and the synergistic effects between Cu x O core and CoNi-LDH shell can provide abundant active sites, rich open-channels and reduced charge transfer resistance (R ct) for effective oxygen release and facile electron transport. Consequently, the optimized Cu x O@CoNi-LDH/CF exhibits a low overpotential of 207 mV in 1 M KOH solution at the current density of 10 mV cm−2 and a small Tafel slope of 50.1 mV dec−1. After 60 h of long-term stability test, the catalytic performance is only slightly weakened. This work demonstrates a new approach to design the high-performance LDH and Cu-related OER catalysts by constructing a unique hierarchical core–shell nanostructure. [ABSTRACT FROM AUTHOR]