Charge-controlled switchable CO₂ capture and gas separation using BC₃ nanosheets

Area of Science:

• Materials Science
• Computational Chemistry
• Environmental Science

Background:

• Rising atmospheric carbon dioxide (CO2) levels necessitate advanced capture and separation technologies.
• Charge-modulated sorbent materials present a promising avenue for reversible CO2 adsorption.
• Understanding adsorption mechanisms on novel nanomaterials is crucial for developing effective CO2 capture solutions.

Purpose of the Study:

• To investigate the adsorption behavior of CO2 on BC3 nanosheets with varying charge states.
• To explore the potential of charge injection for enhancing CO2 capture capacity and selectivity.
• To evaluate the feasibility of BC3 nanosheets as switchable materials for CO2 capture and storage.

Main Methods:

• Density Functional Theory (DFT) calculations with long-range dispersion correction were employed.
• Simulations studied the adsorption of CO2, H2, CH4, and N2 on pristine and charged BC3 nanosheets.
• Adsorption energies, charge transfer, and desorption barriers were analyzed.

Main Results:

• CO2 adsorption on pristine BC3 is weak, transitioning to strong chemical adsorption upon introduction of negative charges (e.g., 3 e).
• BC3 nanosheets exhibit high CO2 capture capacity (up to 4.30 × 10^14 cm^-2 with 5 e charge injection).
• Negatively charged BC3 demonstrates high selectivity for CO2 over other industrial gases (CH4, H2, N2) and facile CO2 release upon charge removal.

Conclusions:

• Charge-modulated BC3 nanosheets are effective for switchable CO2 capture and storage.
• The reversible chemical adsorption mechanism allows for efficient capture and barrier-free release of CO2.
• These findings provide a theoretical foundation for designing advanced materials for CO2 emission reduction.