Dopamine-modified cobalt spinel nanoparticles as an active catalyst for the acidic oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient non-noble metal electrocatalysts for the oxygen evolution reaction (OER) in acidic media is crucial but challenging.
• Cobalt oxide (Co3O4) is a promising material, but its performance in acidic OER requires enhancement.

Purpose of the Study:

• To engineer a nitrogen-doped carbonaceous component-engineered Co3O4 (NCEC) catalyst.
• To investigate the role of nitrogen-doped carbonaceous components in boosting Co3O4's OER performance.
• To understand the relationship between nitrogen species and catalytic activity.

Main Methods:

• Sol-gel synthesis method for catalyst preparation.
• Electrochemical characterization of OER performance in 1 M H2SO4.
• Density Functional Theory (DFT) calculations to elucidate catalytic mechanisms.

Main Results:

• The optimized NCEC catalyst achieved a low overpotential of 330 mV at 10 mA cm-2.
• The catalyst exhibited excellent long-term stability, maintaining performance for 60 hours.
• Thermodynamic overpotential correlated inversely with oxidized and pyridinic N content, and directly with pyrrolic-N content.
• Enhanced charge transfer and the role of oxidized N species were confirmed by experiments and DFT.

Conclusions:

• Nitrogen-doped carbonaceous components significantly enhance the OER performance of Co3O4 in acidic conditions.
• Oxidized nitrogen species on Co3O4 are key to high catalytic activity.
• Further optimization of NCEC catalysts can be achieved by increasing oxidized N content.