Abstract
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 ultrathin nanosheets on CuxO support (NiFe LDH@CuxO) via microwave-assisted hydrothermal reaction. For OER, the NiFe LDH@CuxO core-shell nanostructured catalyst demonstrated promising electrocatalytic performance, requiring only 1.43 V onset potential 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 electrolyte 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.
The NiFe-LDH@CuxO core-shell architecture was synthesized in two steps through co-precipitation and microwave-assisted hydrothermal reaction, and their electrochemical activity for OER in alkaline media was investigated. When compared to pristine NiFe LDH, the fabricated NiFe-LDH@CuxO core-shell architectures provide more electrochemical active sites, lower interfacial charge transfer resistance, and effectively prevent agglomeration and restacking, enhancing their electrochemical stability.. [Display omitted]
•NiFe LDH@CuxO core-shell nanostructures were fabricated using the microwave-assisted hydrothermal method.•NiFe LDH@CuxO exhibits a much lower onset-potential of 1.43 V to start OER, even outperforming iridium oxide (IrO2).•NiFe LDH@CuxO required an overpotential of 270 mV to deliver a current density of 10 mA cm−2.•The unique core–shell 3D structure effectively prevents the agglomeration and restacking NiFe-LDH nanosheet.