Construction of Co,N-Coordinated Carbon Dots for Efficient Oxygen Reduction Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal-doped carbon dots (CDs) are explored for oxygen reduction reaction (ORR) catalysis.
• The specific roles of metal doping on binding sites and formation mechanisms in CDs remain unclear.

Purpose of the Study:

• To investigate the influence of cobalt (Co) doping on the catalytic performance of carbon dots (CDs).
• To explore the formation mechanisms and binding sites influenced by Co doping in CDs.
• To develop high-performance electrocatalysts for zinc-air batteries.

Main Methods:

• Facile synthesis of Co,N-doped CDs via low-temperature polymerization-solvent extraction from EDTA-Co.
• Preparation of Co,N-doped CDs on carbon black (Co-CDs@CB) using a hydrothermal route.
• Characterization of catalytic performance for ORR and application in zinc-air batteries.

Main Results:

• Co doping significantly increased pyridinic-N active sites in CDs (from 4.2% to 11.27%).
• Uniform distribution of Co-CDs on carbon black (CB) enhanced active site exposure.
• Co-CDs@CB exhibited superior ORR catalytic activity attributed to a synergistic Co,N effect.
• The composite nanomaterial demonstrated good cycle stability in high-performance zinc-air batteries.

Conclusions:

• Co doping is advantageous for forming pyridinic-N active sites, boosting ORR performance.
• The Co,N synergistic effect in Co-CDs@CB offers a novel metal doping mechanism for advanced electrocatalysts.
• Co-CDs@CB composites are promising for high-performance, stable zinc-air batteries.