In situ growth of 3D walnut-like nano-architecture Mo-Ni2P@NiFe LDH/NF arrays for synergistically enhanced overall water splitting

Abstract The in situ growth of nano-array on material structure is a novel and high-efficient strategy to design catalysts, however, it still remains a challenge to fabricate unique nano-architecture electrocatalyst with prominent activity and superior durability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, a unique nano-architecture catalyst is successfully synthesized by using NiFe LDH nanosheets as framework to the in situ growth Mo-doped Ni2P ultrafine nanosheets (marked as Mo-Ni2P@NiFe LDH/NF). The unique 3D core-shell nano-architecture is favorable for enhancing electron transfer/mass diffusion, providing abundant active sites, prompting O2/H2 gas release, and creating the synergistic effect between Mo-Ni2P and NiFe LDH. Therefore, comparing with pure NiFe LDH/NF and Mo-Ni2P/NF electrodes, walnut-like Mo-Ni2P@NiFe LDH/NF catalyst exhibits significantly improved electrocatalytic activities and durability towards OER (269 mV @ 40 mA cm−2), HER (82 mV @ 10 mA cm−2), and overall water splitting (1.46 V @ 10 mA cm−2), respectively. Such electrocatalytic activity of Mo-Ni2P@NiFe LDH/NF is comparable with that of majority reported non-precious metal catalysts and even precious catalysts (IrO2 and Pt/C). This work presents a new perspective strategy to fabricate ingeniously bifunctional electrocatalysts with well-designed structure and superior performance for clean energy conversion technologies or storage devices.