Ultrafast transformation of metal-organic frameworks into advanced oxygen evolution electrocatalysts with good universality and scalability

Developing efficient and low-cost electrocatalysts to accelerate the sluggish kinetics of the oxygen evolution reaction (OER) is of great significance for energy conversion technologies. Herein, an ultrafast room-temperature method is demonstrated for converting bimetallic CoNi metal-organic frameworks (MOFs) into high-performance OER catalysts consisting of Fe incorporating CoNi hydroxides and MOFs (denoted as Fe-CoNi MOFs). This straightforward approach not only introduces OER-favoring Fe into the catalyst to ameliorate the electronic conductivity for rapid charge transfer, but also engineers the CoNi MOFs into hierarchical micro-nano-architectures with a high density of active sites and rich boundary defects. Consequently, the Fe-CoNi MOFs catalyst exhibits excellent OER activity with a low overpotential of 230 mV at 10 mA cm(-2) and a high turnover frequency of 2.75 s(-1) at an overpotential of 340 mV, along with superior durability over 100 h of operation in 1 M KOH. Further analysis reveals that the in situ formed metal oxyhydroxides on the catalyst surface are the real OER active species, and the incorporated Fe effectively regulates the local electronic configurations of the neighboring Co site for more favorable adsorption of the *OH intermediate to reduce the energy barrier of the rate-determining step. This ultrafast Fe incorporation method is also successfully applied to boost the OER performance of many other MOFs as well as to synthesize large-size electrodes. With good universality and scalability, this work opens up a cost-effective route to transform MOF-based materials into advanced nanoarchitectures for energy conversion applications.

Automated summary

This paper presents an ultrafast room-temperature method to convert bimetallic CoNi metal-organic frameworks (MOFs) into high-performance OER catalysts consisting of Fe incorporating CoNi hydroxides and MOFs. The Fe-CoNi MOFs catalyst exhibits excellent OER activity with low overpotential and high turnover frequency, along with superior durability. In situ formed metal oxyhydroxides on the catalyst surface and the regulated electronic configurations by incorporated Fe contribute to the enhanced OER performance.