Sacrificial-Agent-Triggered Mass Transfer Gating in Covalent Organic Framework for Hydrogen Peroxide Photocatalysis

Area of Science:

• Materials Science
• Photocatalysis
• Green Chemistry

Background:

• Covalent organic framework (COF) photocatalysts face challenges in H₂O₂ production due to mass transport limitations and inefficient charge separation.
• Existing methods struggle to optimize interfacial reactions for efficient photocatalytic hydrogen peroxide generation.

Purpose of the Study:

• To develop a novel mass-transfer gating (MTG) strategy for enhanced photocatalytic H₂O₂ production using benzothiazole-COFs.
• To investigate the synergistic effects of benzyl alcohol (BA) in improving COF photocatalyst performance and reaction mechanisms.
• To demonstrate the practical application of the generated H₂O₂ in degrading organic pollutants for wastewater treatment.

Main Methods:

• Synthesis of benzothiazole-based COFs (Tp-BTz COF and Tp-TTz COF).
• Implementation of a sacrificial agent-triggered mass-transfer gating (MTG) strategy using benzyl alcohol (BA).
• Evaluation of photocatalytic H₂O₂ production efficiency in various water systems and assessment of generated H₂O₂ for pollutant degradation (MO, RhB).

Main Results:

• The MTG strategy with BA significantly enhanced H₂O₂ yield to 100.9 mmol g⁻¹ h⁻¹ for Tp-BTz COF, surpassing previous records.
• Tp-BTz COF and Tp-TTz COF exhibited durable H₂O₂ production efficiency in high-salinity seawater and tap water.
• Generated H₂O₂ effectively degraded methyl orange (MO) and rhodamine B (RhB), showcasing wastewater treatment potential.

Conclusions:

• The developed MTG strategy effectively reconfigures interfacial reactions, enhancing mass transport, catalytic site accessibility, and charge separation for COF photocatalysts.
• Benzyl alcohol acts synergistically as a proton source, hole scavenger, and modulator of interfacial reactions, leading to superior H₂O₂ production.
• This approach provides a generalizable platform for designing high-performance photocatalytic systems for sustainable energy and environmental remediation.