Amide Covalent Bonding Engineering in Heterojunction for Efficient Solar-Driven CO₂ Reduction

Area of Science:

• Materials Science
• Photocatalysis
• Green Chemistry

Background:

• Inefficient charge separation and slow interfacial reactions limit photocatalytic CO2 reduction.
• Developing advanced heterojunction photocatalysts is crucial for efficient CO2 conversion.

Purpose of the Study:

• To engineer heterojunction photocatalysts with enhanced charge separation and interfacial dynamics.
• To synthesize amide-bonded carbon quantum dot-graphitic carbon nitride (CQD-CN) for improved CO2 reduction.

Main Methods:

• Utilized an EDC/NHS-assisted linking strategy to form amide covalent bonds between CQDs and g-C3N4.
• Synthesized CQD-CN heterojunction photocatalysts.
• Investigated photocatalytic CO2 reduction performance and stability.

Main Results:

• The synthesized CN-CQD photocatalysts demonstrated efficient carrier migration, CO2 adsorption, and activation.
• Achieved high CO and CH4 evolution rates (79.2 and 2.7 μmol g-1 h-1), significantly outperforming controls.
• Exhibited exceptional stability over 12 hours of continuous testing.
• Identified COOH* as a key intermediate species in CO2 to CO conversion.

Conclusions:

• Covalent bonding engineering via amide linkages effectively enhances charge separation in heterojunction photocatalysts.
• The developed CQD-CN material presents a promising strategy for efficient solar-driven CO2 reduction.
• This approach offers a pathway for designing high-performance photocatalysts for sustainable chemical synthesis.