Synergetic Cobalt-Copper-Based Bimetal-Organic Framework Nanoboxes toward Efficient Electrochemical Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient oxygen electrocatalysts are crucial for energy conversion and storage.
• Understanding catalytic mechanisms is key to developing high-performance systems.

Purpose of the Study:

• To develop novel CoCu-based bimetallic metal-organic framework nanoboxes (CoCu-MOF NBs) for efficient electrochemical oxygen evolution reaction (OER).
• To investigate the catalytic mechanism underlying the OER performance of these nanoboxes.

Main Methods:

• Fabrication of CoCu-MOF NBs using a successive cation and ligand exchange strategy.
• Electrochemical characterization of OER activity and stability.
• Quasi in situ X-ray absorption fine structure spectroscopy and density-functional theory calculations to elucidate the catalytic mechanism.

Main Results:

• CoCu-MOF NBs exhibit excellent OER activity with a low overpotential of 271 mV at 10 mA cm⁻².
• High turnover frequency of 0.326 s⁻¹ at 300 mV overpotential was achieved.
• The nanoboxes demonstrated superior stability during the OER process.

Conclusions:

• The post-formed CoCu-based oxyhydroxide analogue is responsible for the high OER activity.
• Electronic synergy between Co and Cu atoms enhances O-O bond coupling, leading to fast OER kinetics.