Accessing local electron-beam induced temperature changes during <i>in situ</i> liquid-phase transmission electron microscopy

Fritsch, Birk; Hutzler, Andreas; Wu, Mingjian; Khadivianazar, Saba; Vogl, Lilian; Jank, Michael P. M.; März, Martin; Spiecker, Erdmann

doi:10.1039/d0na01027h

Cited by 39 publications

(32 citation statements)

References 47 publications

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“…S16). Under these electron beam conditions, a rise in temperature during the imaging was estimated to be less than a few kelvins (section S7) (26,(64)(65)(66). The movies were recorded at a frame rate of 7.5 frames per second.…”

Section: Liquid-phase Temmentioning

confidence: 99%

Real-space imaging of nanoparticle transport and interaction dynamics by graphene liquid cell TEM

et al. 2021

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Thermal motion of colloidal nanoparticles and their cohesive interactions are of fundamental importance in nanoscience but are difficult to access quantitatively, primarily due to the lack of the appropriate analytical tools to investigate the dynamics of individual particles at nanoscales. Here, we directly monitor the stochastic thermal motion and coalescence dynamics of gold nanoparticles smaller than 5 nm, using graphene liquid cell (GLC) transmission electron microscopy (TEM). We also present a novel model of nanoparticle dynamics, providing a unified, quantitative explanation of our experimental observations. The nanoparticles in a GLC exhibit non-Gaussian, diffusive motion, signifying dynamic fluctuation of the diffusion coefficient due to the dynamically heterogeneous environment surrounding nanoparticles, including organic ligands on the nanoparticle surface. Our study shows that the dynamics of nanoparticle coalescence is controlled by two elementary processes: diffusion-limited encounter complex formation and the subsequent coalescence of the encounter complex through rotational motion, where surface-passivating ligands play a critical role.

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Section: Liquid-phase Temmentioning

confidence: 99%

Real-space imaging of nanoparticle transport and interaction dynamics by graphene liquid cell TEM

et al. 2021

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“…[16,17] To enable LP-TEM becoming a standard characterization method this needs to be accounted for appropriately. Besides electron-beam induced heating, [18,19] radiolysis is a crucial factor during LP-TEM, [20][21][22][23] even when radical scavengers are utilized [24,25] or radiolytic shielding via graphene membranes is employed. [26,27] Moreover, radiation chemistry has been identified as a prime driving force to study both reductive formation, [28][29][30] and oxidative etching [31][32][33][34][35] of metallic nanostructures.…”

Section: Introductionmentioning

confidence: 99%

Radiolysis‐Driven Evolution of Gold Nanostructures – Model Verification by Scale Bridging In Situ Liquid‐Phase Transmission Electron Microscopy and X‐Ray Diffraction

et al. 2022

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Utilizing ionizing radiation for in situ studies in liquid media enables unique insights into nanostructure formation dynamics. As radiolysis interferes with observations, kinetic simulations are employed to understand and exploit beam‐liquid interactions. By introducing an intuitive tool to simulate arbitrary kinetic models for radiation chemistry, it is demonstrated that these models provide a holistic understanding of reaction mechanisms. This is shown for irradiated HAuCl4 solutions allowing for quantitative prediction and tailoring of redox processes in liquid‐phase transmission electron microscopy (LP‐TEM). Moreover, it is demonstrated that kinetic modeling of radiation chemistry is applicable to investigations utilizing X‐rays such as X‐ray diffraction (XRD). This emphasizes that beam‐sample interactions must be considered during XRD in liquid media and shows that reaction kinetics do not provide a threshold dose rate for gold nucleation relevant to LP‐TEM and XRD. Furthermore, it is unveiled that oxidative etching of gold nanoparticles depends on both, precursor concentration, and dose rate. This dependency is exploited to probe the electron beam‐induced shift in Gibbs free energy landscape by analyzing critical radii of gold nanoparticles.

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“…The local temperature inside the cell could be changed by the electron beam. This temperature change can affect the radiochemistry inside the aqueous solution. − In our case, we cannot directly measure the local temperature increase inside the GLCs. The increase in temperature can dry the solvent.…”

Section: Resultsmentioning

confidence: 98%

Direct Imaging of the Atomic Mechanisms Governing the Growth and Shape of Bimetallic Pt–Pd Nanocrystals by In Situ Liquid Cell STEM

2022

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Understanding the atomic mechanisms governing the growth of bimetallic nanoalloys is of great interest for scientists. As a promising material for photocatalysis applications, Pt–Pd bimetallic nanoparticles (NPs) have been in the spotlight for many years due to their catalytic performance, which is typically superior to that of pure Pt NPs. In this work, we use in situ liquid cell scanning transmission electron microscopy to track the exact atomic mechanisms governing the formation of bimetallic Pt–Pd NPs. We find that the formation process of the bimetallic Pt–Pd is divided into three stages. First, the nucleation and growth of ultrasmall primary nanoclusters are formed by the agglomeration of Pt and Pd atoms. Second, the primary nanoclusters are involved in a coalescence process to form two types of bigger agglomerates, namely, amorphous (a-NC) and crystalline (c-NC) nanoclusters. In the third stage, these clusters undergo a coalescence process leading to the formation of Pt–Pd NPs, while, in parallel, monomer attachment continues. We found that the third stage contains three types of coalescence processes, a-NC–a-NC, a-NC–c-NC, and c-NC–c-NC coalescence, which eventually give rise to crystalline bimetallic alloys. However, each type of coalescence gave distinct NPs in terms of shape and defects. Our results thus reveal the exact growth mechanisms of bimetallic alloys on the atomic scale, unravel the origin of their structure, and overall are of key interest to tailor the structure of bimetallic NPs.

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Accessing local electron-beam induced temperature changes during in situ liquid-phase transmission electron microscopy

Abstract: A significant electron-beam induced heating effect is demonstrated for liquid-phase transmission electron microscopy at low electron flux densities using Au nanoparticles as local nanothermometers. The obtained results are in agreement...

Cited by 39 publications

References 47 publications

Real-space imaging of nanoparticle transport and interaction dynamics by graphene liquid cell TEM

Real-space imaging of nanoparticle transport and interaction dynamics by graphene liquid cell TEM

Radiolysis‐Driven Evolution of Gold Nanostructures – Model Verification by Scale Bridging In Situ Liquid‐Phase Transmission Electron Microscopy and X‐Ray Diffraction

Direct Imaging of the Atomic Mechanisms Governing the Growth and Shape of Bimetallic Pt–Pd Nanocrystals by In Situ Liquid Cell STEM

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