Hetero MOF-on-MOF-derived carbon nanotube interconnected nitrogen-doped carbon-encapsulated FeNi/FeF2 for efficient oxygen evolution reaction

Heterostructures derived from metal-organic frameworks (MOFs) with multicomponent synergism are significant in the energy conversion and catalysis reactions. Herein, we demonstrated such an efficient catalyst with the structure of self-catalyzed nitrogen-doped carbon nanotube interconnected FeNi/FeF2 derived from hetero-zeolite imidazolate frameworks 8 (ZIF-8) on Fe2Ni MIL (MIL represents Materials of Institut Lavoisier) for oxygen evolution reaction. The obtained catalyst showed efficient synergism of the multicomponents, high polarity, more active sites exposure, increased intrinsic activity, and improved conductivity and stability by a carbon interconnected and confined structure as revealed by the spectroscopic analysis and electrochemical measurements. It required an overpotential of only ca. 240 mV (no iR correction) to reach the current density of 10 mA cm(-2) in a KOH solution when loaded on an inert glass carbon electrode, much better than similar kinds of catalysts. The improved catalytic performance can be well correlated to the structural transformation step by step from different MOFs to their derivatives by subsequent carbonation and fluorination. Because of the above-mentioned structural advantages, good catalysis performance of high activity and stability, faster catalytic kinetics, and facile active phase formation were observed compared to those of other similar materials. This work offers a new platform of derivatives from hetero MOF-on-MOF for catalysis reactions.

Automated summary

This study demonstrated an efficient catalyst with multicomponent synergy, showing high activity and stability in oxygen evolution reaction through spectroscopic analysis and electrochemical measurements.