Activated carbons modified by magnesium oxide as highly efficient sorbents for acetone

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Chemistry

Background:

• Porous activated carbon (AC) is widely used for gas adsorption.
• Developing efficient AC-based materials for volatile organic compound (VOC) capture is crucial.
• Magnesium oxide (MgO) can enhance the adsorption properties of materials.

Purpose of the Study:

• To synthesize and characterize MgO-modified activated carbon composites for acetone capture.
• To investigate the correlation between the physical/chemical properties of AC-MgO composites and their acetone adsorption capacity.
• To elucidate the adsorption mechanism of acetone on AC-MgO surfaces using computational methods.

Main Methods:

• Evaporation-induced self-assembly (EISA) method for AC-MgO synthesis.
• Characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption isotherms.
• Acetone adsorption experiments and Density Functional Theory (DFT) calculations.

Main Results:

• Five AC-MgO composites were synthesized and characterized, showing varied textural properties and MgO content.
• The AC-MgO-10% sample demonstrated the highest acetone adsorption capacity (432.7 mg g^-1).
• DFT calculations confirmed strong chemisorption between MgO nanoparticles and acetone molecules, explaining the enhanced adsorption.

Conclusions:

• MgO modification significantly enhances the acetone adsorption capacity of porous activated carbon.
• Optimizing MgO content is key to maximizing adsorption performance.
• The enhanced adsorption is attributed to chemisorption facilitated by MgO nanoparticles.