Microwave-assisted growth of spherical core-shell NiFe LDH@CuxO nanostructures for electrocatalytic water oxidation reaction

The high energy demand for electrochemical water splitting arises from sluggish oxygen evolution reaction (OER) kinetics. In this regard, Layered double hydroxide (LDH) has been introduced as an outstanding catalyst for the OER due to its exceptional physiochemical and 2D infrastructure properties. Herein, we report the design and synthesiss of core-shell nanostructured electrocatalyst by rationally decorating vertically oriented NiFe LDH ul-trathin nanosheets on CuxO support (NiFe LDH@CuxO) via microwave-assisted hydro-thermal reaction. For OER, the NiFe LDH@CuxO core-shell nanostructured catalyst demonstrated promising electrocatalytic performance, requiring only 1.43 V onset po-tential and 270 mV overpotential at 10 mA cm-2. The NiFe LDH@CuxO also outperformed pristine NiFe LDH and iridium oxide (IrO2) in terms of electrocatalytic activity, durability, and Faradaic efficiency. The fabricated NiFe-LDH@CuxO electrocatalyst with outer shell NiFe-LDH ultrathin nanosheets provides numerous exposed active sites, benefits elec-trolyte diffusion and oxygen gas releasing and also reduces the interfacial charge transfer resistance to enhance OER activity. Furthermore, exclusive core-shell 3D infra-structure effectively prevents NiFe-LDH nanosheets agglomeration and restacking, enhancing electrochemical stability.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, a core-shell nanostructured electrocatalyst, NiFe LDH@CuxO, was designed and synthesized by decorating vertically oriented NiFe LDH ultra-thin nanosheets on CuxO support via a microwave-assisted hydrothermal reaction. The NiFe LDH@CuxO catalyst demonstrated promising electrocatalytic performance for the oxygen evolution reaction (OER), with an onset potential of 1.43 V and an overpotential of 270 mV at 10 mA cm-2. It outperformed pristine NiFe LDH and iridium oxide (IrO2) in terms of electrocatalytic activity, durability, and Faradaic efficiency. The unique core-shell 3D structure effectively prevented aggregation and restacking of the NiFe LDH nanosheets, enhancing the electrochemical stability.