APTES-Based Silica Nanoparticles as a Potential Modifier for the Selective Sequestration of CO₂ Gas Molecules

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Silica nanoparticles (SiO2) are versatile materials with tunable properties.
• Effective carbon dioxide (CO2) capture remains a critical challenge in environmental science.
• Nanomaterials offer potential for improved gas sorption due to high surface area.

Purpose of the Study:

• To characterize hybrid silica nanoparticles for CO2 sorption.
• To evaluate the impact of size and surface modification on CO2 capture.
• To assess the CO2/N2 selectivity of the developed materials.

Main Methods:

• Synthesis and characterization of 50 nm and 200 nm SiO2 nanoparticles.
• Surface modification using 3-aminopropyl (triethoxysilane) (APTES).
• Techniques included UV-Vis, IR, SEM, AFM, and CO2 sorption/desorption isotherms.
• Ideal Absorbed Solution Theory (IAST) for selectivity analysis.

Main Results:

• APTES-modified SiO2 nanoparticles exhibited significantly enhanced CO2 sorption (0.80 mmol/g at 50 °C) compared to bare SiO2 (0.57 mmol/g).
• Smaller 50 nm nanoparticles showed higher CO2 capture efficiency than 200 nm counterparts due to increased micropore volume.
• CO2/N2 selectivity exceeded 70 at both 25 and 50 °C, comparable to leading microporous materials.

Conclusions:

• Hybrid silica nanoparticles, particularly the 50 nm APTES-modified variants, are highly effective for CO2 capture.
• The results highlight the importance of nanoparticle size and surface functionalization for gas sorption.
• These materials show promise as efficient solutions for carbon sequestration technologies.