Interfacial engineering induced highly efficient CoNiP@NiFe layered double hydroxides bifunctional electrocatalyst for water splitting

Reasonably constructing heterostructure is an efficient strategy to improve the intrinsic activity of catalyst for both hydrogen and oxygen evolution reactions. Herein, a heterostructure of CoNiP and NiFe layered double hydroxides (CoNiP@NiFe LDHs) is successfully prepared via a quick two-step electrodeposition method. The electrons rearrangement at the interface composed of CoNiP and NiFe LDHs promoted by the disparity of their unique work functions can increase the electron density of CoNiP, further optimizing the Gibbs free energy for the adsorption of hydrogen. Thus, CoNiP@NiFe LDHs need a low overpotential of 68 mV to reach 10 mA cm⁻². Meanwhile, the modulated valence band energy level (E_VB) and holes collection at the space charge region of NiFe LDHs layer significantly enhance the oxygen evolution reaction performance of CoNiP@NiFe LDHs, which presents a low overpotential of 255 mV at 50 mA cm⁻². The assembled electrolyzer using CoNiP@NiFe LDHs as electrodes also exhibits a low cell voltage of 1.59 V at 50 mA cm⁻².