ZnO/Carbon Spheres with Excellent Regenerability for Post-Combustion CO₂ Capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Developing efficient carbon capture materials is crucial for mitigating climate change.
• Porous carbon materials offer potential for carbon dioxide (CO2) adsorption.
• Incorporating metal oxides can enhance the adsorption properties of carbon materials.

Purpose of the Study:

• To synthesize and characterize ZnO/carbon sphere composites.
• To investigate the effect of activation and zinc nitrate modification on CO2 adsorption capacity.
• To evaluate the cyclic stability of the synthesized materials for CO2 capture.

Main Methods:

• Solvothermal synthesis using resorcinol-formaldehyde resin and zinc nitrate, microwave heating.
• Activation with potassium oxalate and modification with zinc nitrate.
• CO2 adsorption/desorption experiments using thermogravimetric analysis at 40 °C.
• Cyclic stability testing over multiple adsorption-desorption cycles.

Main Results:

• ZnO/carbon spheres were successfully synthesized.
• Activation and zinc nitrate modification generally enhanced CO2 adsorption capacity.
• The highest CO2 adsorption capacity (2.08 mmol/g) was achieved with potassium oxalate activation and high zinc nitrate content.
• The materials demonstrated excellent cyclic stability with <10% performance decay over 25 cycles.

Conclusions:

• ZnO/carbon sphere composites are effective CO2 adsorbents.
• Potassium oxalate activation and zinc nitrate modification optimize adsorption performance.
• The synthesized materials exhibit high potential for practical CO2 capture applications due to their stability.