Amorphous Metal-Organic Framework-Dominated Nanocomposites with Both Compositional and Structural Heterogeneity for...

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Amorphous metal-organic frameworks (aMOFs) are promising materials but typically require harsh synthesis conditions.
• Complex aMOFs with diverse compositions and structures are seldom reported, limiting their application potential.

Purpose of the Study:

• To synthesize a structurally and compositionally complex amorphous metal-organic framework nanocomposite (aMOF-NC) using a facile approach.
• To investigate the synthesis mechanism and electrochemical performance of the novel aMOF-NC.

Main Methods:

• Facile synthesis of aMOF-NC with a core-shell nanorod@nanosheet architecture.
• Experimental characterization and density functional theory (DFT) calculations to elucidate the ligand-competition amorphization mechanism.
• Electrochemical testing for oxygen evolution reaction (OER) activity.

Main Results:

• Successful synthesis of a complex aMOF-NC featuring a Fe-rich Fe-Co-aMOF core and a Co-rich Fe-Co-aMOF shell, topped with amorphous Co(OH)2 nanosheets.
• Proposed and validated a ligand-competition amorphization mechanism.
• Achieved excellent OER activity with a low overpotential (249 mV at 10 mA cm⁻²) and a low Tafel slope (39.5 mV dec⁻¹).

Conclusions:

• The facile synthesis approach enables the creation of complex aMOF-NCs.
• The structural and compositional heterogeneity of the aMOF-NC is key to its enhanced electrochemical performance.
• The developed aMOF-NC shows significant potential for efficient oxygen evolution reactions.