Improving CO₂ photoconversion with ionic liquid and Co single atoms.

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Photocatalytic CO2 conversion offers a sustainable pathway for solar energy storage.
• Challenges include slow electron kinetics and poor product selectivity.
• Developing efficient photocatalysts is crucial for CO2 utilization.

Purpose of the Study:

• To develop an efficient photocatalyst for CO2 and water conversion into valuable chemicals.
• To investigate the synergistic effects of ionic liquids and single-atom catalysts on g-C3N4 nanosheets.
• To enhance electron transfer kinetics and product selectivity in photocatalysis.

Main Methods:

• Synthesis of ultrathin g-C3N4 nanosheets.
• Loading of 1-ethyl-3-methylimidazolium tetrafluoroborate (ionic liquid) and borate-anchored Co single atoms.
• Photocatalytic CO2 reduction experiments under UV-vis irradiation.
• In-situ μs-transient absorption spectroscopy for electron transfer analysis.
• Density functional theory (DFT) calculations for mechanistic insights.

Main Results:

• The optimized nanocomposite exhibited a 42-fold increase in photoactivity compared to pristine g-C3N4.
• Achieved nearly 100% selectivity for CO2 reduction to CO and CH4.
• Demonstrated a maximum electron transfer efficiency of 35.3% for CO2 photoreduction.
• The ionic liquid facilitated electron extraction and CO2 reduction, while Co single atoms catalyzed water oxidation.

Conclusions:

• The synergistic effect of the ionic liquid and Co single atoms on g-C3N4 nanosheets significantly enhances photocatalytic CO2 conversion.
• This strategy provides an efficient route for converting CO2 into valuable fuels and chemicals.
• The developed photocatalyst shows great potential for solar energy storage and CO2 utilization applications.