Nitrogen Plasma Activates CoMn-Layered Double Hydroxides for Superior Electrochemical Oxygen Evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Bimetallic layered double hydroxides (LDHs) are promising electrocatalysts but suffer from poor electrical conductivity.
• Developing facile strategies to enhance the activity and stability of LDH catalysts is crucial for efficient oxygen evolution reactions (OER).

Purpose of the Study:

• To develop a simple and effective method for synthesizing highly active and stable nitrogen-doped bimetallic layered double hydroxide catalysts.
• To investigate the role of nitrogen doping and oxygen vacancies in enhancing the electrocatalytic performance for OER.

Main Methods:

• Corrosion strategy and nitrogen plasma technology were employed to convert cobalt-based metal-organic frameworks into nitrogen-doped CoMn-LDH.
• Electrochemical measurements (overpotential, current density) and Density Functional Theory (DFT) calculations were used to evaluate catalytic performance and understand the reaction mechanism.

Main Results:

• N@CoMn-LDH/CC demonstrated a low overpotential of 219 mV at 10 mA cm⁻², outperforming commercial RuO₂.
• DFT calculations revealed that nitrogen doping optimizes Mn site adsorption energy and reduces the Co site reaction barrier for OER.
• The OER mechanism was confirmed to follow the lattice oxygen oxidation mechanism, enhancing structural stability.

Conclusions:

• The developed N@CoMn-LDH/CC catalyst offers a superior and stable electrocatalytic performance for OER.
• This work presents a novel and facile strategy for designing advanced catalysts for efficient oxygen evolution.