A Method for Determining Incorporation Depth in Core-Shell UiO-66 Nanoparticles Synthesized Via Postsynthetic...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Post-synthetic exchange (PSE) is crucial for modifying metal-organic frameworks (MOFs).
• Previous studies on linker distribution in MOFs focused on larger crystals, neglecting nanoparticles.
• Nanoparticle MOFs are vital for applications like CO2 adsorption and catalysis, often exhibiting core-shell structures via PSE.

Purpose of the Study:

• To investigate the formation of core-shell structures in MOF nanoparticles using diffusion-controlled PSE.
• To develop a simple method for calculating the minimum linker incorporation depth in MOF nanoparticles.
• To validate the proposed calculation method against experimental data.

Main Methods:

• Diffusion-controlled post-synthetic exchange (PSE) on MOF nanoparticles.
• Analysis of volume-to-surface ratios and time-dependent experiments.
• Development of a calculation for minimum incorporation depth based on particle size and linker amount.
• Validation using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX).

Main Results:

• Diffusion-controlled PSE conditions were confirmed to promote core-shell architecture formation in MOF nanoparticles.
• A straightforward method to calculate the minimum incorporation depth was successfully developed.
• The calculation method demonstrated accuracy when validated against TEM-EDX data.

Conclusions:

• This research elucidates the formation of core-shell structures in MOF nanoparticles via PSE under diffusion control.
• The developed method provides a valuable tool for understanding and predicting linker incorporation in MOF nanoparticles.
• Findings pave the way for designing advanced MOF core-shell nanostructures for targeted applications.