Defect-Conjugation Coupling in Sulfur and Carbon Co-doped Poly(triazine imide) for Visible-Light-Driven H₂O₂...

Area of Science:

• Materials Science
• Photocatalysis
• Green Chemistry

Background:

• Crystalline poly(triazine imide) (PTI) shows potential for solar-driven oxygen reduction to hydrogen peroxide (H2O2).
• Performance limitations include poor visible-light absorption and charge transport due to defect-mediated recombination.

Purpose of the Study:

• To develop a strategy for enhancing PTI's optoelectronic properties for improved H2O2 production.
• To investigate the effects of sulfur (S) and carbon (C) co-doping on PTI's crystalline structure and photocatalytic activity.

Main Methods:

• Molten-salt synthesis of sulfur and carbon co-doped PTI (S, C-PTI).
• Characterization using spectroscopy and structural analysis.
• Density functional theory (DFT) calculations to understand doping effects on reaction intermediates.

Main Results:

• S, C-PTI exhibits enhanced visible-light absorption and a narrowed band gap due to synergistic S and C doping.
• Codoping reorganizes electronic structure, suppresses recombination, and creates active sites for O2 reduction.
• S, C-PTI achieves a 7-fold and 16-fold higher H2O2 generation rate compared to pristine PTI and polymeric carbon nitride, respectively.

Conclusions:

• Non-metal co-doping is an effective strategy for tuning PTI's crystallinity and optoelectronic properties.
• S, C-PTI demonstrates a significant advancement in solar-to-chemical conversion for H2O2 production.
• This work provides a pathway for designing advanced crystalline photocatalysts.