Micro-Reactor Chip for Real-Time Observing Metal-Organic Framework (MOF) nanocrystals grown under in-situ transmission Electron microscopy

This work reports a new method for real-time observing the growth process of metal-organic framework (MOF) nanocrystals under in-situ TEM (transmission electron microscopy). For MOF grown via gas-solid reaction, the ligands should be firstly vaporized and then introduced to the surface of metal-contained building-blocks for further gas-solid reaction. One challenge for in-situ TEM observing MOF growth process lies in that it is difficult to directly introduce the solid-state ligand molecules into micro-reactor. Herein, a micro-reactor integrated with SiN
_x
observing windows, gas channel and micro-heater is fabricated for gas-solid growing MOF nanocrystals. The ligand molecules are previously encapsulated in mesoporous silica particles (MSNs) and then sustained released to avoid blocking the tiny capillary channel of the micro-reactor. By using the new method, dynamic process of vaporized H
₃
BTC (trimesic acid) ligands reacting with ZnO nanowires for Zn
₃
(BTC)
₂
nanocrystal growing is successfully observed.