Solvent Engineering and Metal-Doping Dual Effects Enable Morphology Precise Controlled MOF-based Electrocatalysts for...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Economically viable electrocatalysts with high activity are crucial for the oxygen evolution reaction (OER) in water electrolysis for renewable hydrogen generation.
• Current challenges lie in designing materials that offer superior performance and stability for practical applications.

Purpose of the Study:

• To design and synthesize a novel electrocatalyst, CoFe-MOF(W), for efficient oxygen evolution reaction (OER) catalysis.
• To investigate the synergistic effects of solvent engineering and metal doping on the electrocatalytic activity and mechanism.

Main Methods:

• Fabrication of a layered CoFe-MOF(W) catalyst using a dual-regulation mechanism involving solvent engineering and Fe-doping.
• Electrocatalytic performance evaluation for OER, including overpotential and Tafel slope measurements.
• Mechanistic studies involving surface reconstruction analysis and density-functional theory (DFT) calculations.

Main Results:

• The CoFe-MOF(W) catalyst demonstrated superior OER performance, requiring only 276 mV overpotential at 10 mA cm⁻² and exhibiting a Tafel slope of 55 mV dec⁻¹.
• Solvent engineering induced unsaturated coordination states and exposed more active sites, while Fe-doping enhanced charge transfer and electronic structure.
• Surface reconstruction yielded Co(Fe)OOH as the active species, and DFT calculations confirmed optimized *OH adsorption for enhanced kinetics.

Conclusions:

• The study presents a new insight into using solvent modulation and metal doping strategies for metal-organic framework (MOF)-based electrocatalysts.
• The developed CoFe-MOF(W) catalyst shows significant promise for efficient OER and applications in sustainable energy systems.
• This work provides a pathway for designing advanced electrocatalysts for water electrolysis.