Strategic drive toward bi-linker MOFs: an efficient electrocatalyst for hydrogen and oxygen evolution reactions

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalyst design for overall water splitting faces challenges in conductivity, kinetics, and stability.
• Conventional single-linker metal-organic frameworks (MOFs) often exhibit limitations in bifunctional electrocatalytic performance.

Purpose of the Study:

• To engineer a novel copper-based MOF with a dual-linker architecture for enhanced overall water splitting.
• To overcome the inherent trade-offs between conductivity, kinetics, and stability in electrocatalysts.

Main Methods:

• Synthesized a copper-based MOF incorporating 1,2,4,5-benzenetetracarboxylic acid (H4BTEC) and 2-methylimidazole (2-MIM) linkers.
• Conducted comprehensive electrochemical characterization, including overpotential, Tafel slope, and charge-transfer resistance measurements.
• Utilized morphological and structural analyses to confirm the hierarchical porous structure.

Main Results:

• The dual-linker Cu-MOF electrode exhibited significantly lower overpotentials: 234.7 mV for HER and 169.8 mV for OER.
• Achieved record-low Tafel slopes (18.1 mV dec−1 for HER, 71.6 mV dec−1 for OER) and reduced charge-transfer resistance (1.1 Ω).
• Demonstrated superior performance compared to single-linker MOF analogues.

Conclusions:

• The strategic integration of bifunctional linkers in Cu-MOFs offers a new paradigm for designing high-performance, non-precious metal electrocatalysts.
• This molecular engineering approach effectively resolves the conductivity-kinetics-stability trade-off in electrocatalysis.
• The developed MOF is a promising candidate for efficient and sustainable hydrogen production via water splitting.