Construction of Ni2P@NiCo-BLDH nanocomposite with hierarchical porous structure on nickel foam as advanced oxygen evolution electrocatalyst

The fabrication of two-dimensional layered double hydroxides (LDHs) materials still faces great challenges, particularly in achieving precise modulation of lamellar metals and interlayer anions for electrocatalytic oxygen evolution reaction (OER). Herein, a hierarchical porous nanocomposite assembled by foam nickel (NF) supported borate anions incorporated bimetallic NiCo hydrotalcite (NiCo-BLDH) on the surface of nickel phosphide sheets (NF/Ni2P @ NiCo-BLDH) is prepared through the NF in-situ phosphating and electrodeposition approach as an electrocatalyst for achieving superior OER catalysis. In this design, introducing multi-phase and incorporated borate anions into LDHs can regulate their structure and properties, creating unique active sites and enhancing the adsorption efficiency of OH- to effectively improve the OER activity. Remarkably, the NF/Ni2P @ NiCo-BLDH electrode shows a low overpotential of 293 mV at 100 mA cm-2 for OER and a Tafel slope of 108.3 mV dec-1 in a 1.0 M KOH medium, surpassing most previously reported NiCo-based catalysts. Nevertheless, the NF/Ni2P electrode exhibits a lower overpotential for the hydrogen evolution reaction (HER) in a 1.0 M KOH medium compared to the NF/Ni2P @ NiCo-BLDH electrode. This work not only advances the catalytic activity of the NiCo-LDH-based materials in OER but also provides a new idea for large-scale electrocatalytic water splitting applications.