Electronic Structure Engineering of Carbon Nitride Materials by Using Polycyclic Aromatic Hydrocarbons

Area of Science:

• Materials Science
• Photocatalysis
• Semiconductor Chemistry

Background:

• Efficient charge separation is crucial for semiconductor photocatalysts.
• Designing materials with specific electronic structures remains a challenge.
• Modified carbon nitride materials offer potential for improved photo(electro)catalytic applications.

Purpose of the Study:

• To synthesize modified carbon nitride materials (CNs) with tunable donor-acceptor (D-A) domains.
• To investigate the impact of polycyclic aromatic hydrocarbon (PAH) conjugation degree on material properties and photocatalytic activity.
• To enhance charge separation and photo(electro)catalytic performance for hydrogen evolution.

Main Methods:

• Synthesis of new monomers based on PAH-substituted 1,3,5-triazine.
• Embedding monomers within cyanuric acid-melamine supramolecular assemblies to form CN precursors.
• Systematic variation of PAH conjugation degree (benzene to pyrene) and characterization of resulting materials.

Main Results:

• Successful synthesis of modified carbon nitride materials with D-A domains and altered electronic structures.
• Demonstrated correlation between PAH conjugation degree and material morphology, structure, electronic properties, and photocatalytic activity.
• Achieved excellent photocatalytic activity and long-term stability for hydrogen evolution reaction.
• PAH-CNs films exhibited enhanced charge separation, optical absorption, electrochemical surface area, and electronic conductivity.

Conclusions:

• The strategic design of D-A sites in carbon nitride materials significantly enhances photocatalytic and photoelectrochemical performance.
• Tuning the conjugation degree of embedded PAHs is an effective strategy to optimize material properties for energy applications.
• Developed materials show great promise for efficient and stable hydrogen production via photocatalysis and photoelectrocatalysis.