Synergistic Visible-Light-Driven CO₂ Reduction and H₂O Oxidation over Ti₃C₂ Quantum Dot-Modified Cu/g-C₃N₄...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Artificial photosynthesis aims to convert CO2 into valuable fuels using sunlight.
• Challenges include rapid charge recombination and limited thermodynamic driving force in photocatalytic CO2 reduction.
• Developing efficient photocatalysts is crucial for sustainable energy solutions.

Purpose of the Study:

• To design and synthesize a novel ternary heterojunction photocatalyst for enhanced CO2 reduction.
• To investigate the role of zero-dimensional Ti3C2 quantum dots (QDs) and metallic Cu in a g-C3N4 framework.
• To improve charge separation, light absorption, and catalytic activity for solar-driven CO2 conversion.

Main Methods:

• Fabrication of a ternary heterojunction photocatalyst (CCNT) using 0D Ti3C2 QDs and metallic Cu on 2D g-C3N4.
• Characterization of the material's structure, optical, and electronic properties.
• Evaluation of photocatalytic performance for CO2 reduction to CO and CH4 under visible light, including stability tests.

Main Results:

• The optimized CCNT-5 composite demonstrated high CO and CH4 production rates (24.59 and 20.24 μmol g-1 h-1, respectively).
• Achieved excellent electron selectivity (94.90%) towards CO2 reduction with simultaneous water oxidation.
• The catalyst exhibited superior charge separation and stability due to the synergistic effects of Ti3C2 QDs and Cu nanoparticles.

Conclusions:

• The developed 0D/metal/2D heterojunction architecture effectively suppresses charge recombination and enhances photocatalytic CO2 reduction.
• The ternary photocatalyst shows significant potential for efficient and stable solar-driven fuel production.
• This work provides a rational design strategy for advanced artificial photosynthesis systems.