Mapping nanocrystalline disorder within an amorphous metal–organic framework

DOI: 10.1038/s42004-023-00891-9

Authors: Adam F. Sapnik (University of Cambridge) , Chao Sun (University of Leeds) , Joonatan E. M. Laulainen (University of Cambridge) , Duncan N. Johnstone (University of Cambridge) , Rik Brydson (University of Leeds) , Timothy Johnson (Johnson Matthey Technology Centre) , Paul A. Midgley (University of Cambridge) , Thomas D. Bennett (University of Cambridge) , Sean M. Collins (University of Cambridge; University of Leeds)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Communications Chemistry , VOL 6

State: Published (Approved)
Published: May 2023
Diamond Proposal Number(s): 20198

Abstract: Intentionally disordered metal–organic frameworks (MOFs) display rich functional behaviour. However, the characterisation of their atomic structures remains incredibly challenging. X-ray pair distribution function techniques have been pivotal in determining their average local structure but are largely insensitive to spatial variations in the structure. Fe-BTC (BTC = 1,3,5-benzenetricarboxylate) is a nanocomposite MOF, known for its catalytic properties, comprising crystalline nanoparticles and an amorphous matrix. Here, we use scanning electron diffraction to first map the crystalline and amorphous components to evaluate domain size and then to carry out electron pair distribution function analysis to probe the spatially separated atomic structure of the amorphous matrix. Further Bragg scattering analysis reveals systematic orientational disorder within Fe-BTC’s nanocrystallites, showing over 10° of continuous lattice rotation across single particles. Finally, we identify candidate unit cells for the crystalline component. These independent structural analyses quantify disorder in Fe-BTC at the critical length scale for engineering composite MOF materials.

Subject Areas: Chemistry, Materials

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E02-JEM ARM 300CF

Added On: 12/05/2023 08:57

Discipline Tags:

Chemistry Materials Science Chemical Engineering Engineering & Technology Metal-Organic Frameworks Metallurgy

Technical Tags:

Microscopy Electron Microscopy (EM) Scanning Electron Microscopy (SEM) Scanning Transmission Electron Microscopy (STEM)