NANOSENSORS’ Post

Exciting TEM development: in liquid-cell TEM electrified solid-liquid atomic dynamics development using advanced polymer electrochemical liquid cells for transmission electron microscopy (TEM). Zheng (LBNL) and team were able to directly monitor the atomic dynamics of ESLIs during copper (Cu)-catalysed CO2 electroreduction reactions (CO2ERs). Observed results were of a fluctuating liquid-like amorphous interphase, undergoing reversible crystalline– amorphous structural transformations and flows along the electrified Cu surface. These dynamics mediated the crystalline Cu surface restructuring and mass loss through the interphase layer. Combining real-time observations and theoretical calculations revealed an amorphization-mediated restructuring mechanism resulting from charge-activated surface reactions with the electrolyte. In situ TEM allows the tracking of individual nanocatalyst evolutions during reactions, but the spatial information has so far been limited to imaging through liquids under electric biasing. Many opportunities ensue from this work to explore the atomic dynamics and its impact in broad systems involving ESLIs by taking advantage of the in situ imaging capability. Congratulations to Qiubo Zhang, Zhigang Song, Xianhu Sun, Yang Liu, Jiawei Wan, Sophia Betzler, Qi Zheng, Junyi Shangguan, Karen Bustillo, Peter Ercius, Prineha Narang, Yu Huang & Haimei Zheng Lawrence Berkley Labs #Research #Nanoelectronics #ElectronMicroscopy #STEMResearch #microscopy #electronmicroscopy #subsampling #imaging #Atomicelectrontomography #transmissionelectronmicroscopy #TEM #2DSTEM #4DSTEM #scanningelectronmicroscopy #nanomaterials #electronscattering #thinfilms #nanofabrication #Electrifiedsolidliquidinterfaces #electrochemistry

Long awaiting research article published in Materials Today Advances as first and corresponding author, Impact factor: 10. This article demonstrates on the quantification of atomic sites in two dimensional layered material alloy called MoS2(1-x)Se2x using atomic resolution high angle annular dark field scanning transmission electron microscopy (HAADF - STEM) technique including Auger electron spectroscopy, Raman and photoluminescence spectroscopy techniques. We have stressed more on persistent photoconductivity and photoelectrocatalysis mechanism due to these alloy states and defects in the MoS2(1-x)Se2x system.

How can graphene be used as a working electrode in liquid-electrochemical microscopy? Saltanat Toleukhanova, Vasiliki Tileli, and their colleagues at EPFL published recent work characterizing graphene as a working electrode for CO2 electroreduction (CO2ER) of Cu nanocatalysts with the Hummingbird Scientific Generation V bulk liquid-electrochemical SEM system (https://lnkd.in/gsU3xEm). The graphene membrane served as the sample carrier, working electrode, and liquid sealing membrane. Electrochemical liquid-phase SEM (ec-LPSEM) enabled imaging of Cu nanocube degradation processes under CO2ER. Cyclic voltammetry (CV) plots indicated a wider inert cathodic range for the graphene working electrode than glassy carbon. Keeping the probe current low enabled imaging of nanocube degradation and secondary particle deposition at the CO2ER operating potential of -1.1 V vs. RHE. The team demonstrated the advantages of the graphene working electrode in liquid electron microscopy cells, towards multiscale imaging of electrochemically-driven processes. See the comments below for a link to the full paper.    Follow Hummingbird Scientific to stay up to date on the latest in-situ TEM news. #TEM #SEM #electrocatalysis #hummingbirdscientific #nanotechnology #materialsscience #nanocubes #graphene #2Dmaterials

🔬✨ Our latest research article has been published in Surface Engineering and Applied Electrochemistry, uncovering the secrets of gold nanoparticle (Au NPs) thin films. 📊🔍 📝 Publication Title: "Tuning the Morphological and Optical Properties of Pulsed Laser-Deposited Gold Nanoparticle Thin Films by Varying Number of Laser Pulses" 🔍 Abstract: Our study explores the impact of varying the number of laser pulses on the morphology and optical properties of gold (Au) NPs thin films deposited on a glass substrate at 300°C. Through scanning electron microscopy, UV-visible spectroscopy, and photoluminescence studies, we delve into the changes in particle size, inter-particle distance, and film thickness. 🔬 Key Findings: Particle size increased from 14 to 28 nm, while inter-particle distance decreased from 19 to 8 nm with an increase in laser pulses from 1000 to 5000. Thickness of Au NPs film grew from 107.5 to 132.4 nm. SPR peak observed around 565–586 nm confirmed Au NPs formation, with a redshift attributed to enhanced particle size and reduced inter-particle distance. Photoluminescence spectrum exhibited a strong emission band at 530 nm, corresponding to an energy band gap of 2.34 eV, in agreement with SPR peak position. 🔬 Significance: Our findings shed light on the tunability of SPR properties of Au NPs by adjusting the number of laser pulses, offering insights into the design of chemical and biomolecule sensors with improved performance. 📚 Read the Full Article: https://lnkd.in/g6Mc8upe 🙌 Join the Discussion: Curious to learn more about our research? Feel free to comment below and engage with us! #Nanotechnology #SurfaceEngineering #OpticalProperties #PlasmonicSensors #ResearchPublication

Controlled single-electron transfer enables time-resolved excited-state spectroscopy of individual molecules. An increasing number of scanning-probe-based spectroscopic techniques provides access to diverse electronic properties of single molecules. Typically, these experiments can only study a subset of all electronic transitions, which obscures the unambiguous assignment of measured quantities to specific quantum transitions. Here they have developed a single-molecule spectroscopy that enables the access to many quantum transitions of different types, including radiative, non-radiative and redox, that is, charge-related, transitions. https://lnkd.in/gNnAz-uN

Delving into Material Science: A comprehensive review discusses the integration of high-pressure techniques with time-resolved transient absorption spectroscopy, revealing critical insights into the ultrafast dynamics of materials. This approach is vital for enhancing material performance in optoelectronics, offering a detailed examination of the structural and optical property relationships. #MaterialScience #spectroscopy

🌟 How Does Surface Roughness Impact the Mechanics of Nano-Objects? 🌟 We are excited to share our latest study, recently published in Acta Materialia, where we used molecular dynamics simulations to compress gold nanoparticles roughened with our free tool, Pyrough. 🔍 Our findings reveal that nanoparticles with rough surfaces—featuring steps as small as a single interatomic layer—can be weakened by up to 90% compared to perfectly flat samples! These insights offer a new perspective on interpreting the data scattering often observed in nanomechanics experiments. 👉 Learn more by reading the full publication in Acta Materialia. #CNRS #AMU #IM2NP #ActaMaterialia #Nanotechnology #MaterialsScience #Research #Innovation #MolecularDynamics #Nanomechanics https://lnkd.in/djj6DG2v

How can electron tomography signals be combined to reduce beam exposure? Jonathan Schwartz, Robert Hovden, and their colleagues at the University of Michigan, Argonne National Laboratory, Northwestern University, University of California, Berkeley, Berkeley Lab, Cornell University, and Dow. published work using the Hummingbird Scientific tomography sample holder (https://lnkd.in/e-DciNN) to perform 3D electron tomography on highly beam sensitive nanoscale samples. The team combined elastic HAADF and inelastic EDX/EELS signals perform low-dose high resolution chemical tomography. Using fused multi-modal electron tomography, 3D chemical mapping was achieved in three beam sensitive materials with resolution near or below 1 nm, with multi-modal tomography yielding a 3-5 fold improvement in simulated recovery error over conventional chemical tomography. The high tilt angle, and rotational stability of the Hummingbird Scientific tomography holder combined with this novel technique will enable higher resolution 3D chemical imaging of beam sensitive materials, accelerating development of nanomaterial synthesis, processing, and characterization. See the comments below for a link to the full paper.    Follow Hummingbird Scientific to stay up to date on the latest in-situ TEM news. #tomography #hummingbirdscientific #nanomaterials #materialsscience #STEM #metrology #multimodal #EDS #EELS

Quantification of three-dimensional atomic distribution of different in microporous materials is very important especially in the field of catalysis as presence of different atomic species in the microporous channels of catalysts such as MOFs and zeolites could block the active sites, degrading the performance of the catalyst. However, due to availability of state-of-the-art aberration correctors, it has been possible to image materials at sub-Å scales, the class of materials mentioned above exhibit high radiation sensitivity. Furthermore, HRTEM or ADF and (A)BF STEM techniques, often exhibit non-linearity in imaging process due to specimen dependent transfer functions and coherent illumination respectively. HAADF can produce linear and interpretable images due to incoherent nature and this could be used for quantitative analysis. However, it is much less sensitive to the light elements and highly dose-inefficient to image beam-sensitive materials. Now, researchers from Technische Universität Graz including Prof. Ferdinand Hofer using a probe-corrected Thermo Fisher Scientific Titan³ microscope have performed quantification of three-dimensional distribution of single Cs atomic species distributed in microporous natural beryl (Be₃Al₂Si₆O₁₈) channels from a single projection HAADF image at relatively low electron dose. HAADF, unlike (A)BF, is robust to thickness and defocus related contrast reversals and contrast hardly deteriorates due to small thickness or defocus variation. This is due to the fact that most of the contrast in HAADF is obtained through electron channeling effect and therefore the optimum contrast is obtained at zero defocus relative to the top of the sample (probe is focused exactly at the sample entrance). However, in case of significant defocus, this channeling effect reduces resulting in poor contrast. This is the reason why researchers weren't able to identify even heavy atoms like Cs located deep into the beryl channels. Though, HAADF worked well for identifying Cs atoms, light atoms such as 3d transition metals and light alkali and alkaline earth metals were almost invisible and for thicker beryl samples, even Cs was found difficult to identify. Though iDPC-STEM is a dose-efficient as well as linear imaging method, it is reliable only for thin samples and for thicker samples quantitative analysis could result in error and practical minimum thickness for this sample is 10 nm. Additionally, thickness is an important parameter for quantitative atomic resolution analysis. However, thickness measurement methods such as PACBED and EELS aren't very useful for beam-sensitive materials as they'll destroy the sample before the analysis is completed. Nevertheless, researchers used the same image as they used for atomic quantification combined with multislice simulations for thickness estimation. Read interesting findings published in the journal Communications Materials. https://lnkd.in/dxGfyjhC

An interesting technique🔎.... High-Resolution Transmission Electron Microscopy (HRTEM) is an analytical technique in materials science used to obtain detailed images at the atomic or molecular scale. In this method a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through. Information Attained from HRTEM: 1. Atomic Structure: provides detailed information about the atomic arrangement within materials. This includes the identification of crystal structures, d- spacing, diffraction patterns, defects, dislocations, interfaces and phase distribution between different materials. Such detailed structural information is crucial for understanding material properties and behaviour. 2. Nanomaterials Characterization: HRTEM is invaluable in the study of nanoscale materials such as nanoparticles, nanowires, nanotubes, and thin films. It helps in determining particle shapes, sizes, and the arrangement of nanoparticles within a larger matrix. 3. Chemical Composition: While HRTEM itself does not provide direct chemical composition, it can be coupled with techniques such as energy-dispersive X-ray spectroscopy (EDX) to provide elemental composition and distribution at the nanoscale. A video 🎥 of the Cu grid used in HRTEM with particles dispersed.