Electron-beam-induced structural degradation in two representative 2D MOFs: a ligand-dependent comparison

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Two-dimensional metal-organic frameworks (2D-MOFs) show potential in separations, sensing, and nano-optoelectronics.
• Electron beam fabrication and imaging of 2D-MOFs are hindered by structural damage.

Purpose of the Study:

• To investigate how ligand chemistry influences electron beam-induced structural damage in 2D-MOFs.
• To quantify degradation pathways and critical doses for specific 2D-MOFs.
• To establish practical guidelines for low-dose electron microscopy and electron beam lithography.

Main Methods:

• Low-dose serial electron diffraction at 300 kV was used to analyze electron beam responses.
• Degradation mechanisms and critical doses were quantified for Zn-TCPP and Zn2(benzimidazolate)4.
• Ligand-resolved dose thresholds were extracted.

Main Results:

• Zn-TCPP shows a two-stage degradation: initial ligand-assisted rearrangement followed by unit cell collapse.
• Zn2(benzimidazolate)4 undergoes direct amorphization due to Zn-N4 breakdown.
• Specific dose thresholds and practical windows for electron beam applications were determined.

Conclusions:

• Ligand chemistry is a key factor in the electron beam response of 2D-MOFs.
• Electron beam can be utilized as a design tool for 2D-MOFs, not just a source of damage.
• This research provides a framework for advanced low-dose characterization and fabrication of 2D-MOFs.