Constructing an Active Sulfur-Vacancy-Rich Surface for Selective *CH₃-CH₃ Coupling in CO₂-to-C₂H₆ Conversion With 92%...

Area of Science:

• Materials Science
• Catalysis
• Environmental Science

Background:

• Photocatalytic CO2 reduction to C2+ products requires efficient CO2 adsorption and low energy barriers for key intermediates.
• Plasmonic materials can generate hot electrons, creating environments conducive to multielectron reactions.

Purpose of the Study:

• To develop a photocatalyst that enhances CO2 adsorption and facilitates C-C coupling for selective C2+ production.
• To investigate the role of plasmonic MoO3-x in a ZnIn2S4-based photocatalyst for CO2 reduction.

Main Methods:

• Synthesis of ZnIn2S4 (ZIS)/MoO3-x (Z-M) composite photocatalyst.
• Density Functional Theory (DFT) calculations to analyze reaction mechanisms and energy barriers.
• Experimental evaluation of photocatalytic CO2 reduction under visible light.

Main Results:

• The Z-M photocatalyst exhibits enhanced CO2 adsorption and activation due to sulfur vacancies created by MoO3-x.
• DFT calculations show preferential pathways for C2H6 formation over C2H4 due to lower energy barriers for CH3-CH3 coupling.
• The Z-M catalyst achieved a CO2-to-C2H6 conversion rate of 467.3 µmol g-1 h-1 with 92.0% selectivity under visible light.

Conclusions:

• The plasmonic MoO3-x component in the Z-M photocatalyst plays a dual role in enhancing CO2 adsorption and promoting C2+ production.
• The Z-M photocatalyst demonstrates significant potential for selective and efficient conversion of CO2 into valuable hydrocarbons like ethane.