Structural and Morphological Conversion between Two Co-Based MOFs for Enhanced Water Oxidation.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and cost-effective water oxidation catalysts is crucial for energy conversion and storage.
• Metal-organic frameworks (MOFs) offer tunable structures for catalytic applications.

Purpose of the Study:

• To synthesize and characterize two new MOFs, BMM-11 and BMM-12.
• To investigate their transformation into active electrocatalysts for the oxygen evolution reaction (OER).

Main Methods:

• Solvothermal synthesis of BMM-11 and BMM-12 from cobalt nitrate and H4BPTC.
• Single-crystal-to-single-crystal transformation between the MOFs.
• Electrocatalytic testing for OER.
• Post-electrolysis characterization using microscopy and spectroscopy.

Main Results:

• BMM-11 and BMM-12 were successfully synthesized and interconverted.
• Direct electrocatalytic application led to MOF degradation into active CoO(OH) species (CoOOH and Co(OH)2).
• Achieved stable current densities of 10 mA cm-2 at low overpotentials (0.362 V for BMM-11, 0.393 V for BMM-12).

Conclusions:

• MOF degradation under OER conditions generates highly active cobalt oxyhydroxide species.
• This MOF transformation approach provides a viable route to advanced electrocatalysts for water splitting.
• Strategies like doping and grinding can further enhance catalytic performance.