Novel Cerium-Based Sulfide Nano-Photocatalyst for Highly Efficient CO₂ Reduction

Area of Science:

• Materials Science
• Photocatalysis
• Environmental Chemistry

Background:

• Excessive carbon dioxide (CO2) emissions drive the need for efficient CO2 conversion technologies.
• Photocatalysis offers a promising strategy for converting CO2 into valuable chemicals.
• Rare-earth materials are increasingly explored for advanced catalytic applications.

Purpose of the Study:

• To investigate the potential of rare-earth sulfide nanocrystals, specifically NaCeS2, as photocatalysts for CO2 conversion.
• To elucidate the crucial role of Cerium (Ce) ions in the photocatalytic mechanism.
• To enhance CO2 conversion efficiency through heterostructure design.

Main Methods:

• Fabrication and characterization of NaCeS2 nanocrystals.
• Investigation of the electronic band structure and its relation to Ce ion hybridization (Ce 4f and Ce 5d orbitals).
• Design and testing of a NaCeS2-MoS2 heterostructure for improved photocatalytic activity.

Main Results:

• NaCeS2 exhibits a photoresponsive band structure due to Ce ion orbital hybridization.
• The material demonstrates excellent charge separation efficiency and CO2 adsorption affinity.
• The NaCeS2-MoS2 heterostructure significantly boosted the CO2 to CO conversion yield from 7.24 to 23.42 µmol g-1 in 9 hours, outperforming TiO2 controls.

Conclusions:

• NaCeS2 is an effective rare-earth-based photocatalyst for selective CO2 to CO conversion.
• Ce ion electronic properties are critical for enhancing charge separation and CO2 adsorption.
• Heterostructure engineering provides a viable pathway to further optimize photocatalytic performance for CO2 utilization.