Co-doped NiFe-LDH nanosheets arrays supported on nickel foam as an efficient oxygen evolution electrocatalysis

Co2+ doping can efficiently enhance NiFe-LDH oxygen evolution electrocatalysis performance (According to theoretical calculation, Fe:Co=2:1 has a good activity, conforming to experimental findings.) and has good long-term stability under commercial high current density conditions of 500 and 1000 mA cm−2. [Display omitted] •A Co-introduced fine-modulated NiFe-LDH performance strategy is proposed to construct a Co-doped NiFe LDH nanosheet arrays supported by nickel foam.•The as-obtained Co-NiFe-LDH/NF exhibits remarkable electrocatalytic performance for OER in a 1.0 M KOH alkaline solution, and represents high potential for commercial application.•Co2+ doping can efficiently enhance NiFe-LDH oxygen evolution electrocatalysis performance (According to theoretical calculation, Fe:Co = 2:1 has a good activity, conforming to experimental findings). In the field of water electrolysis for hydrogen production, NiFe-layered double hydroxides (NiFe-LDH) is currently one of the most excellent oxygen evolution electrocatalyst. However, its application in this field is limited due to its low durability, low conductivity and few active sites. In this work, we present a Co-introduced fine-modulated NiFe-LDH performance strategy to construct Co-doped NiFe-LDH nanosheets arrays supported on nickel foam (Co-NiFe-LDH/NF). The optimized Co-NiFe-LDH/NF showed ultralow overpotentials at 211, 237, 261 and 281 mV at 50, 100, 200 and 300 mA cm−2 current densities, separately, with an extremely low Tafel slope (40 mV dec−1). The Co-NiFe-LDH/NF was highly stable during the constant current test, and the potential increased by only 10 and 13 mV after 100 h stability test at 200 and 300 mA cm−2. Notably, it also works stably at the 500 and 1000 mA cm−2 very high current densities, representing high potential of commercial application. The theoretical calculation showed that: (1) Introducing Co into NiFe-LDH can reduce the energy barrier of OH* conversion to O* and increase the activity of OER; (2) Considering the formation energy, Co is more likely to replace Fe site in NiFe-LDH than Ni site; (3) The energy barrier, differential charge and partial density of states analysis show that the best OER performance is obtained when the Fe-to-Co ratio of 2:1, and the theoretical calculation is consistent with the experimental verification. This work provides a simple and effective method for the design and construction of doping elements into NiFe-LDH electrocatalysts for efficient water oxida