Microbial-vulcanized organic-inorganic dual-modulated cobalt hydroxide for oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for water electrolysis.
• Non-noble metal catalysts require upgrading for industrial applications.
• Developing cost-effective and high-performance electrocatalysts remains a challenge.

Purpose of the Study:

• To develop an efficient chemical modification strategy for cobalt hydroxide-based electrocatalysts.
• To investigate an organic-inorganic dual-modulation approach for enhanced electrocatalytic activity.
• To understand the mechanism behind the improved performance.

Main Methods:

• Synthesized a cobalt hydroxide electrocatalyst (MEC-17) using a microbial-mediated vulcanization method.
• Employed an organic-inorganic dual-modulation strategy with 2-methylimidazole and inorganic sulfur.
• Utilized operando characterizations and theoretical calculations to analyze the catalyst's properties and mechanism.

Main Results:

• The modified electrocatalyst achieved an overpotential of 285.6 ± 1.7 mV for the oxygen evolution reaction.
• Demonstrated over 300 hours of durability at a high current density of 1000 mA cm⁻².
• Sulfur doping shortened Co-Co distances, while 2-methylimidazole modulated Co sites' d-band center, optimizing intermediate adsorption and O-O coupling.

Conclusions:

• The organic-inorganic dual-modulation strategy effectively enhances cobalt hydroxide electrocatalysts.
• The study provides insights into designing hybrid electrocatalysts and understanding their activity origins.
• This work contributes to advancing electrocatalyst technology for water electrolysis.