Promoted Hydrogen Peroxide Production from Pure Water on g-C₃N₄ with Nitrogen Defects Constructed through...

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Graphitic carbon nitrides (g-C3N4) are explored as metal-free piezo-photocatalysts for hydrogen peroxide (H2O2) production.
• Low Lewis-acid properties of g-C3N4 limit oxygen (O2) adsorption and catalytic performance.
• Developing efficient g-C3N4-based catalysts is crucial for sustainable H2O2 synthesis.

Purpose of the Study:

• To enhance the catalytic performance of g-C3N4 for H2O2 production via O2 reduction reaction (ORR).
• To investigate the role of nitrogen vacancies and oxygen functional groups in improving g-C3N4's Lewis acid-base properties.
• To elucidate the catalytic mechanisms of H2O2 formation using light and ultrasound.

Main Methods:

• Synthesis of g-C3N4 with nitrogen vacancies via thermal shocking polymerization using various solvents.
• Characterization of synthesized g-C3N4 materials.
• Investigation of piezo-photocatalytic activity for H2O2 production under light and ultrasound irradiation.
• Mechanistic studies involving radical and water oxidation pathways.

Main Results:

• Synthesized g-C3N4 with nitrogen vacancies and oxygen functional groups showed significantly enhanced catalytic performance.
• Improved Lewis acid-base interactions and lattice polarization led to higher O2 adsorption efficacy.
• Mechanistic studies confirmed H2O2 formation via radical and water oxidation pathways, with light and ultrasound playing key roles.
• A facile one-step method for scalable photocatalyst fabrication was demonstrated.

Conclusions:

• Modified g-C3N4 with nitrogen vacancies offers a promising metal-free photocatalyst for efficient H2O2 production.
• The enhanced Lewis acid-base properties are key to improved catalytic activity.
• This work provides a scalable and sustainable approach for in situ solar H2O2 generation, advancing practical applications.