Sustainable CO₂ Capture Using Porous CuBDC Monoliths via Pickering Foam Templating Reinforced with Bacterial...

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Metal-organic frameworks (MOFs) possess high porosity but suffer from poor processability and mechanical instability in powder form.
• Shaping MOFs into monoliths can overcome these limitations, but traditional methods are often multi-step, use organic solvents, and degrade porosity.
• Developing scalable, sustainable methods for MOF monolith fabrication is crucial for practical applications.

Purpose of the Study:

• To develop a green, one-step strategy for fabricating hierarchically porous MOF monoliths.
• To utilize Pickering foam templating for in situ MOF growth without surfactants or harmful solvents.
• To investigate the mechanical reinforcement of MOF monoliths using bacterial cellulose.

Main Methods:

• Fabrication of ultrastable aqueous foams using CuO nanoparticles modulated by hexanoic acid.
• In situ conversion and growth of MOFs (CuBDC and HKUST-1) at the air-water interface using the foam as a template.
• Incorporation of bacterial cellulose as a reinforcing scaffold into the MOF monoliths.

Main Results:

• Successfully synthesized hierarchically porous MOF monoliths via Pickering foam templating in a single step.
• CuBDC monoliths exhibited well-defined hollow spherical shells templated from foam bubbles.
• Bacterial cellulose incorporation significantly enhanced compressive strength while largely preserving hierarchical porosity.
• The MOF monoliths demonstrated promising CO2 adsorption capacity (2.42 × 10^-1 mmol g^-1 at 298 K).

Conclusions:

• Pickering wet foam serves as an effective direct template for MOF monoliths, offering a sustainable and tunable approach.
• This method overcomes limitations of traditional MOF shaping techniques, enabling scalable fabrication.
• The resulting MOF monoliths show significant potential for gas storage, separation, and adsorption applications.