Designing a spontaneously deriving NiFe-LDH from bimetallic MOF-74 as an electrocatalyst for oxygen evolution reaction in alkaline solution

The increase of high energy resource demand has led to the rapid development of clean fuel of hydrogen by efficiently electrolytic water splitting. However, considering the sluggish kinetics of the oxygen evolution reaction (OER) as the the bottleneck in its electrochemical activity, it is desirable to develop water oxidation electrocatalysts operating under alkaline conditions. Herein, in this study, an effective precursor conversion by a bimetallic metal-organic framework (MOF) is proposed for the first time for fabricating the NiFe layered double hydroxide (LDH) via spontaneously deriving process in the alkaline electrolyte without any additional treatments. The bimetallic MOF-74-derived NiFe LDH provided desirable hot spots for electrocatalizing OER in alkaline solution and facilitated electrolyte penetration within the uniform channel in an organized nanostructure to further increase the contact area between the active material and electrolyte. Compared to pristine NiFe LDH and commercial RuO2, MOF-74-derived NiFe LDH shows higher electroactivity with a promising overpotential of 299 mV to reach a current density of 10 mA cm(-2) and a lower Tafel slope of 48.7 mV dec(-1) in 1.0 M KOH. This study proposes a facile and easy strategy to design a bimetallic MOF-derived LDH with various metallic combinations and ratios for application in different applications.

Automated summary

This study proposed a method to fabricate NiFe LDH through an effective precursor conversion by bimetallic MOF, which exhibited excellent performance in catalyzing OER and operated under alkaline conditions. Compared to other materials, MOF-74-derived NiFe LDH demonstrated higher electroactivity and a lower Tafel slope, showing promising potential for various applications.