A novel 3D CoNiCu-LDH@CuO micro-flowers on copper foam as efficient electrocatalyst for overall water splitting

The superior advantage of electrochemical water splitting for sustainably producing hydrogen has stimulated the rational design and preparation of cost-effective, efficient, and durable bi-functional electrocatalysts. Herein, we present a strategy to fabricate 3D CoNiCu-LDH@CuO heterostructures by a three-step method. With in situ growing Cu(OH)2 nanorod arrays on copper foam, a tri-metallic CoNiCu-BDC MOF with uniform dispersion was formed on the substrate, which can be transferred to a 3D CoNiCu-LDH with a micro-flower structure. The constructed CoNiCu-LDH@CuO/CF self-supporting electrode displays good performance in alkaline media, obtaining low overpotentials of 262 mV and 286 mV at a relatively large current density of 100 mA cm-2 for HER and OER, respectively. Detailed characterizations reveal that the improved HER and OER activity are ascribed to the rich active sites, tight contact between CoNiCu-LDH and substrate, and lower charge-transfer resistance.