Liquid Cell Transmission Electron Microscopy

Abstract

Liquid cell transmission electron microscopy (TEM) has attracted significant interest in recent years. With nanofabricated liquid cells, it has been possible to image through liquids using TEM with subnanometer resolution, and many previously unseen materials dynamics have been revealed. Liquid cell TEM has been applied to many areas of research, ranging from chemistry to physics, materials science, and biology. So far, topics of study include nanoparticle growth and assembly, electrochemical deposition and lithiation for batteries, tracking and manipulation of nanoparticles, catalysis, and imaging of biological materials. In this article, we first review the development of liquid cell TEM and then highlight progress in various areas of research. In the study of nanoparticle growth, the electron beam can serve both as the illumination source for imaging and as the input energy for reactions. However, many other research topics require the control of electron beam effects to minimize electron beam damage. We discuss efforts to understand electron beam-liquid matter interactions. Finally, we provide a perspective on future challenges and opportunities in liquid cell TEM.

Advances in Graphene‐Based Liquid Cell Electron Microscopy: Working Principles, Opportunities, and Challenges

“…[14] Recent developments in microchip fabrication have revolutionized in situ TEM, where thin layers of liquid can be sandwiched between two silicon nitride (SiN) chips, thus being protected from the vacuum during microscopy. [4,5,[18][19][20][21] However, attaining high resolution images in silicon-microfluidic cells is not straightforward, since the image resolution is constrained by the thickness of the silicon nitride windows and the spacing between them. Considering the effect of SiN membrane bulging under high vacuum, the thickness of such liquid cells can reach a few micrometers, resulting in poor signal-to-noise ratio (SNR).…”

“…Among various endeavors to address this obstacle, two solutions stand out: installation of differential pumping column between the electron source and the sample chamber to gradually reach ambient conditions (environmental TEM) or separating the sample from the vacuum column using thin impermeable membranes . Recent developments in microchip fabrication have revolutionized in situ TEM, where thin layers of liquid can be sandwiched between two silicon nitride (SiN) chips, thus being protected from the vacuum during microscopy . However, attaining high resolution images in silicon‐microfluidic cells is not straight‐forward, since the image resolution is constrained by the thickness of the silicon nitride windows and the spacing between them.…”

In Situ Transmission Electron Microscopy Study of Nanocrystal Formation for Electrocatalysis

“…With the quantum advances in the electron microscopy and microfabrication, in‐situ transmission electron microscopy (TEM) emerged as the times require . The rapid development of in‐situ TEM technique provides great opportunities for dynamic study of electrocatalyst formation in liquid and gas phase .…”

“…[35] With the quantum advances in the electron microscopy and microfabrication, in-situ transmission electron microscopy (TEM) emerged as the times require. [35][36] The rapid development of in-situ TEM technique provides great opportunities for dynamic study of electrocatalyst formation in liquid [37][38] and gas phase. [39][40] After integrating with energy-dispersive X-ray spectroscopy (EDS) [41] and electron energy loss (EELS) techniques, [42] it becomes powerful to track the structural and compositional transformation during the electrocatalyst formation.…”

Visualization of Electrochemical Reaction Dynamics in Liquids Using TEM

“…Assisted by electrochemical liquid environmental cells, dynamic phenomena at electrode-electrolyte interfaces can be revealed in real time with high spatial resolution using TEM. So far, there have been many studies, for instance, electrochemical deposition of metal clusters, dendrite formation, using a custom-made or commercial liquid sample stage [1]. Here, using our own development of electrochemical cells and a sample stage, we have been able to observe a series of electrochemical phenomena at electrode-electrolyte interfaces.…”