Phase Engineering and Dispersion Stabilization of Cobalt toward Enhanced Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Phase engineering enhances catalyst activity for hydrogen evolution reaction (HER).
• Metastable phases in polymorphic interfaces lead to instability.
• Developing stable and active HER catalysts is crucial for energy applications.

Purpose of the Study:

• To simultaneously achieve phase engineering and dispersion stabilization for cobalt catalysts.
• To boost HER activity and stability of cobalt-based catalysts.
• To provide an alternative approach for designing advanced HER catalysts.

Main Methods:

• Plasma cathodic electrodeposition for preparing cobalt films with hetero-phase structure.
• Molybdenum doping to reduce stacking fault energy and induce cobalt polymorphs.
• High-temperature plasma discharge for creating oxide/carbide nanoparticles.

Main Results:

• A hetero-phase cobalt structure with rich polymorphism interfaces was successfully synthesized.
• Homogeneously dispersed oxide/carbide nanoparticles were formed, enhancing active sites and tuning electronic structure.
• The Co-hybrid/CoO_MoC catalyst demonstrated high HER activity (44 mV at 10 mA cm⁻²) and excellent stability (no degradation after 100 h).
• Oxide/carbide dispersoids effectively prevented phase transitions through grain boundary pinning.

Conclusions:

• Simultaneous phase engineering and dispersion stabilization can significantly enhance HER performance.
• The developed plasma cathodic electrodeposition method is effective for creating advanced HER catalysts.
• The Co-hybrid/CoO_MoC catalyst shows great potential for real-world hydrogen production applications.