A novel bimetallic organic framework catalyst induced by dual-ligand for highly efficient oxygen evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Non-noble electrocatalysts are advancing, with metal-organic frameworks (MOFs) showing promise for oxygen evolution reaction (OER).
• Challenges remain in molecular-level electronic structure modification of MOFs to boost OER activity.
• Noble metal nanomaterials are effective but costly for OER applications.

Purpose of the Study:

• To synthesize and characterize bimetallic CoNi MOFs modified with dual ligands for enhanced OER.
• To investigate the effect of ligand ratio on the OER performance of CoNi MOFs.
• To evaluate the stability of the developed MOFs compared to commercial standards.

Main Methods:

• Hydrothermal synthesis of bimetallic CoNi MOFs using terephthalic acid (A) and 2,5-dihydroxyterephthalic acid (B).
• Tuning the ratio of dual ligands (A and B) to optimize MOF structure and properties.
• Electrochemical testing to assess OER activity, including overpotential and Tafel slope measurements.
• Long-term stability tests comparing modified MOFs with ruthenium dioxide (RuO2).

Main Results:

• Optimized A2.5B-CoNi MOFs demonstrated significantly enhanced OER activity.
• Achieved an overpotential of 300 mV at 10 mA cm⁻² with a low Tafel slope of 45.27 mV dec⁻¹.
• The A2.5B-CoNi MOFs exhibited superior long-term stability compared to commercial RuO2.

Conclusions:

• Dual-ligand modification of CoNi MOFs is an effective strategy to enhance OER performance.
• The developed MOFs present a cost-effective and high-performance alternative to noble metal catalysts for OER.
• This research offers a new direction for designing advanced dual-ligand MOF electrocatalysts.