Microreactor-Based TG–TEM Synchronous Analysis

Abstract

It is challenging to measure the heating-induced mass change of the material during its morphological/structural evolution process. Herein, a silicon microreactor is developed for thermogravimetric−transmission electron microscopy synchronous analysis (TG−TEM synchronous analysis). A self-heating resonant microcantilever for mass-change detection and a dummy microcantilever with electron-beam transparent SiN x windows for in situ TEM imaging are integrated back-to-back inside the microreactor. The TEM resolution of the microreactor reaches the Ångstrom level in an air atmosphere of 100 mbar, and the TGA function is realized by the heatable resonant microcantilever. The TG−TEM synchronous analysis has been successfully used to characterize two Ni(OH) 2 samples. During the in situ TEM observing process, the desorption of the intercalated H 2 O molecules and dehydration of the lattice OH groups in the amorphous Ni(OH) 2 •xH 2 O nanosheets can be clearly distinguished from the microcantilever-based TGA. For single-crystal Ni(OH) 2 nanosheets, the TG−TEM synchronous analysis can distinguish the desorption of physiosorbed water, the condensation of surface OH groups, and the dehydration of lattice OH groups. The amorphous Ni(OH) 2 nanosheets transformed to polycrystalline NiO completed at 290 °C, and the decomposition from the single-crystalline Ni(OH) 2 nanoplates to NiO at 315 °C is also clearly recognized. The proposed microreactor-based TG−TEM synchronous analysis provides an interrelated characterization platform to obtain more comprehensive information on materials.

Review on Microreactors for Photo-Electrocatalysis Artificial Photosynthesis Regeneration of Coenzymes

“…Silicon material is the first material used to prepare microreactors, and its preparation process is mature, with a high manufacturing accuracy, good repeatability, stable properties, and high-temperature and high-pressure resistance, which is suitable for the preparation of various microreactors. Yao et al developed a silicon-based microreactor for the simultaneous analysis of TGA-TEM ( Figure 3 A), which can synchronously and accurately analyze the thermal stability and microscopic characterization of materials, and has obvious advantages in precision, accuracy, and detail [ 65 ]. In addition, silicon has semiconductor characteristics and infrared transparency.…”

“… Materials of microreactor. ( A ) Silicon-based microreactor [ 65 ]. (Copyright © 2022, American Chemical Society) ( B ) Glass-based microreactor [ 68 ].…”

Applications of Graphene in Five Senses, Nervous System, and Artificial Muscles

“…Graphene vibrometer can measure vibration of buildings for Internet of Things applications . Thermogravimetric analysis on a NEMS processed cantilever can detect nanogram samples and single particle, which can be integrated with a TEM system for in situ analysis of single gas molecule . Besides, graphene based microfiber resonators can detect single molecule with selectivity. , In addition, a differential microwave resonator can serve in situ detection of volatile organic compounds .…”

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“…From the thermogravimetric and microscopic data obtained, the observed morphological and structural changes of both samples to a single crystalline NiO phase could be attributed to their respective mass changes by comparing their thermal stabilities. Additionally, the NH 3 gas sensing capabilities of the two samples were determined using TG-TEM and they were able to quantify and compare the activation energies and adsorption enthalpies of the graphene-like and petal-like Ni(OH) 2 samples for NH 3 gas, 75 thus demonstrating in operando gas sensing.…”