Yao Fanglan, Xu Pengcheng, Li Ming, Wang Xuefeng, Jia Hao, Chen Ying, Li Xinxin
State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Anal Chem. 2022 Jun 28;94(25):9009-9017. doi: 10.1021/acs.analchem.2c01051. Epub 2022 Jun 2.
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 windows for in situ TEM imaging are integrated back-to-back inside the microreactor. The TEM resolution of the microreactor reaches the Ångström 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) samples. During the in situ TEM observing process, the desorption of the intercalated HO molecules and dehydration of the lattice OH groups in the amorphous Ni(OH)·HO nanosheets can be clearly distinguished from the microcantilever-based TGA. For single-crystal Ni(OH) 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) nanosheets transformed to polycrystalline NiO completed at 290 °C, and the decomposition from the single-crystalline Ni(OH) 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.
在材料的形态/结构演化过程中，测量加热引起的质量变化具有挑战性。在此，开发了一种用于热重-透射电子显微镜同步分析（TG-TEM同步分析）的硅微反应器。在微反应器内部，背靠背集成了一个用于质量变化检测的自热共振微悬臂梁和一个带有电子束透明氮化硅窗口用于原位TEM成像的虚拟微悬臂梁。该微反应器在100毫巴的空气气氛中的TEM分辨率达到埃级，并且通过可加热的共振微悬臂梁实现了TGA功能。TG-TEM同步分析已成功用于表征两个氢氧化镍样品。在原位TEM观察过程中，基于微悬臂梁的TGA可以清楚地区分非晶态Ni(OH)·H₂O纳米片中嵌入的H₂O分子的解吸和晶格OH基团的脱水。对于单晶Ni(OH)纳米片，TG-TEM同步分析可以区分物理吸附水的解吸、表面OH基团的缩合以及晶格OH基团的脱水。非晶态Ni(OH)纳米片在290°C时转变为多晶NiO，并且在315°C时从单晶Ni(OH)纳米板分解为NiO也清晰可辨。所提出的基于微反应器的TG-TEM同步分析提供了一个相互关联的表征平台，以获取关于材料的更全面信息。
