Synchronous Electrocatalytic Design of Architectural and Electronic Structure Based on Bifunctional LDH-Co3O4/NF toward Water Splitting

The rational design of highly efficient bifunctional electrocatalysts for water splitting is extremely urgent for application in sustainable energy conversion processes to alleviate the energy crisis and environmental pollution. In this work, through simple deposition of layered double hydroxides (LDH) on Co3O4/NF (NF= nickel foam) nanosheets arrays, hierarchical Co3+-rich materials based on LDH-Co3O4/NF are prepared as highly active and stable electrocatalysts for water splitting. The NiFe-LDH-Co3O4/NF demonstrates excellent electrochemical activity with an overpotential of 214 mV for the OER and an overpotential of 162 mV for the HER at 10 mAcm(-2). Such a performance is attributed to the optimized electronic states with a high concentration of Co3+, which improves the intrinsic activity, and the sheet-on-sheet hierarchical structure, which increases the number of active sites. The unique synchronous design of both the architectural and electronic structure of nanomaterials can simultaneously accelerate the reaction kinetics and provide a more convenient charge transfer path. Therefore, the strategy reported herein may open a new pathway for the design of excellent electrocatalysts for water splitting.

Automated summary

In this study, highly efficient bifunctional electrocatalysts for water splitting have been designed by depositing layered double hydroxides (LDH) on Co3O4/NF nanosheets arrays to form Co3+-rich LDH-Co3O4/NF materials. These materials demonstrated excellent electrochemical activity due to the optimized electronic states and unique sheet-on-sheet hierarchical structure, which accelerated reaction kinetics and provided convenient charge transfer pathways. The strategy reported in this work may pave the way for the design of excellent electrocatalysts for water splitting.