Defects Engineering Leads to Enhanced Photocatalytic H₂ Evolution on Graphitic Carbon Nitride-Covalent Organic...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Graphitic carbon nitride nanosheets (CNS) are promising for solar fuel production.
• Defects in CNS cause charge recombination, limiting photocatalytic performance.

Purpose of the Study:

• To synthesize a novel CNS-covalent organic framework (CNS-COF) nanosheet composite.
• To improve charge separation and photocatalytic activity in CNS materials.

Main Methods:

• Synthesized CNS with reduced defects by tuning thermal exfoliation of bulk carbon nitride.
• Modified CNS with trace COF nanosheets via chemical imine bonding.
• Characterized the composite for enhanced electronic coupling and passivation of surface defects.

Main Results:

• Achieved significantly reduced defects in CNS.
• Established strong electronic coupling between CNS and COF.
• Demonstrated enhanced charge separation and photocatalytic activity.
• Reported a hydrogen evolution rate of 46.4 mmol g⁻¹ h⁻¹ with 31.8% apparent quantum efficiency at 425 nm.

Conclusions:

• The CNS-COF nanosheet composite effectively addresses charge recombination in CNS.
• This composite represents a significant advancement in carbon nitride-based photocatalysts for solar fuel production.