Article
Chemistry, Multidisciplinary
Na Yeon Kim, Shaohong Cao, Karren L. More, Andrew R. Lupini, Jianwei Miao, Miaofang Chi
Summary: With the recent development of high-acquisition-speed pixelated detectors, 4D scanning transmission electron microscopy (4D-STEM) has become available in high-resolution electron microscopy. It provides local information on materials that is challenging to extract from bulk techniques and extends conventional STEM imaging. However, the acquisition of 4D-STEM and electron energy loss spectroscopy (EELS) simultaneously is currently not possible due to overlapping detector geometry. This study demonstrates the feasibility of modifying the detector geometry for overcoming this challenge and explores the use of a partial or defective detector for ptychographic structural imaging, enabling simultaneous multi-modal measurements with spectral information added to 4D datasets.
Review
Chemistry, Multidisciplinary
Xingxu Yan, Chaitanya A. Gadre, Toshihiro Aoki, Xiaoqing Pan
Summary: Vibrational EELS is a groundbreaking spectroscopic technique with unmatched energy resolution and spatial resolution, suitable for both organic and inorganic matter in solid state or liquid phase. This review introduces recent advancements and key concepts of the method, compares with other spectroscopic techniques, and discusses future potential applications in research fields centered on catalysts, polymers, and live cells.
TRENDS IN CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Andrey Moiseenko, Dmitry Bagrov, Mikhail F. Vorovitch, Victoria Uvarova, Maxim M. Veselov, Anastasia Kashchenko, Alla L. Ivanova, Dmitry Osolodkin, Alexey M. Egorov, Aydar A. Ishmukhametov, Konstantin Shaitan, Olga S. Sokolova
Summary: This article provides a detailed analysis of the size and structure of the inactivated TBEV vaccine strain, using multiple analytical methods. The results show the monodispersity of the particles and their similarity in size, as well as the presence of specific protein molecules and RNA.
Article
Green & Sustainable Science & Technology
Chun-Hsien Lin, Yi-Che Chen, Pei-Kai Hsu, Alexandre Gloter, Wei-Hsiang Huang, Chi-Liang Chen, Jenn-Ming Song, Shih-Yun Chen
Summary: In this study, a synergetic structural design is developed to improve the photocatalytic performance of the sub-micro core-shell hollow sphere (TiO2@H-CeO2). The improved performance of the composite structure can be attributed to the synergy of different surfaces and interfacial effects caused by the reactions. The deposition of CeO2 particles increases the interfacial area between the CeO2 and TiO2 and facilitates the corresponding charge transfer.
ADVANCED SUSTAINABLE SYSTEMS
(2023)
Article
Materials Science, Multidisciplinary
Sean H. Mills, Steven E. Zeltmann, Peter Ercius, Aaron A. Kohnert, Blas P. Uberuaga, Andrew M. Minor
Summary: Vacancies, which are missing atoms in crystalline materials, can occur at equilibrium or out of equilibrium and are difficult to measure or visualize experimentally. This study presents a method using high-resolution electron microscopy to map vacancy concentrations and their distribution. The method was demonstrated using a model Au thin film and applied to non-equilibrium defects in pure Al. The technique provides direct measurements of vacancy concentrations at the individual defect level in materials in and out of equilibrium.
Article
Materials Science, Multidisciplinary
L. A. Hughes, Benjamin H. Savitzky, Haitao D. Deng, Norman L. Jin, Eder G. Lomeli, Young-Sang Yu, David A. Shapiro, Patrick Herring, Abraham Anapolsky, William C. Chueh, Colin Ophus, Andrew M. Minor
Summary: In this study, a combination of imaging techniques was used to analyze lithium iron phosphate (LixFePO(4)). The results revealed the local structural and chemical variations in LixFePO(4) particles at different stages of delithiation. This study provides important insights into the LixFePO(4) system and the differences between local and global measurements in terms of lattice parameter-composition behavior. It also demonstrates a powerful approach for bridging the gap between local and statistical characterization.
Article
Materials Science, Multidisciplinary
Xiaoyu Liu, Tianzhong Yang, Peilin Lang, Yuan Yao, Xi Shen, Richeng Yu
Summary: Epitaxial CrO2 film was successfully grown on sapphire using CVD method. The interfacial structure and chromium valence distribution were characterized, and the presence of a transition layer was observed.
Article
Chemistry, Multidisciplinary
Jacob Smith, Zhennan Huang, Wenpei Gao, Guannan Zhang, Miaofang Chi
Summary: Cryogenic four-dimensional scanning transmission electron microscopy (4D-STEM) imaging is a valuable technique for studying quantum materials and their interfaces at atomic scale, but its applications are restricted by the instability of cryo-stages and electronics. To address this issue, an algorithm is developed to correct complex distortions in the atomic resolution cryogenic 4D-STEM data sets. This method involves nonrigid registration and affine transformations to minimize information loss in both reciprocal and real spaces, enabling the reconstruction of sample information from 4D-STEM data sets. It is computationally inexpensive, fast, and suitable for on-the-fly data analysis in future in situ cryogenic 4D-STEM experiments.
Article
Chemistry, Physical
Radim Skoupy, Daan B. B. Boltje, Miroslav Slouf, Katerina Mrazova, Tomas Laznicka, Clemence M. Taisne, Vladislav Krzyzanek, Jacob P. P. Hoogenboom, Arjen J. J. Jakobi
Summary: This study presents a quantitative four-dimensional scanning transmission electron microscopy (4D-STEM) imaging technique (q4STEM) for local thickness estimation across amorphous specimens. The method measures spatially resolved diffraction patterns and evaluates the angular distribution of electron scattering or the ratio of integrated virtual dark and bright field STEM signals using Monte Carlo simulations. The method is independent of signal intensity calibrations and only requires knowledge of the detector geometry. The results demonstrate that the method yields robust thickness estimates for sub-micrometer amorphous specimens in different detectors and instruments.
Review
Biochemistry & Molecular Biology
Miguel Ricardo Leung, Tzviya Zeev-Ben-Mordehai
Summary: The different oligomeric forms of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) have defined cellular and subcellular distributions. While crystal structures of AChE and BChE have been available for many years, structures of the physiologically relevant cholinesterase tetramer were only recently solved by cryo-electron microscopy (cryo-EM). The next frontier in cholinesterase structural biology is to image membrane-anchored ChE oligomers directly in their native environment - the cell.
JOURNAL OF NEUROCHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Maeva Chaupard, Jeril Degrouard, Xiaoyan Li, Odile Stephan, Mathieu Kociak, Ruxandra Gref, Marta de Frutos
Summary: Scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS) allows for the analysis of chemical information at the atomic scale. In this study, metal-organic framework nanoparticles (nanoMOFs) were analyzed using low-dose and cryo-TEM conditions. The results demonstrate damage-free analysis of nanoMOFs and provide insights into chemical reactions occurring under electron exposure.
Article
Neurosciences
Vladan Lucic
Summary: This article reviews the importance of electron microscopy in the study of neuronal synapse structures and discusses the use of image processing software methods. Special attention is given to the application of recent cryo-electron microscopy and tomography methods in molecular level analysis.
CURRENT OPINION IN NEUROBIOLOGY
(2022)
Article
Multidisciplinary Sciences
Kayo Nozawa, Yoshimasa Takizawa, Leonidas Pierrakeas, Chizuru Sogawa-Fujiwara, Kazumi Saikusa, Satoko Akashi, Ed Luk, Hitoshi Kurumizaka
Summary: The canonical nucleosome is the major packaging unit of eukaryotic chromatin, and the H3-H4 octasome is a nucleosome-like particle with alternative histone stoichiometry. The structure of the H3-H4 octasome is flexible.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Lunda Shen, Zhaoming Su, Kailu Yang, Cheng Wu, Thomas Becker, Deborah Bell-Pedersen, Junjie Zhang, Matthew S. Sachs
Summary: The study elucidated the mechanism of action of CHX in inhibiting protein synthesis by arresting the ribosome in the classical PRE translocation state, without interfering with A-site reactivity.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Review
Chemistry, Multidisciplinary
Elizaveta Tyukalova, Joseph Vimal Vas, Reinis Ignatans, Aaron David Mueller, Rohit Medwal, Masaaki Imamura, Hironori Asada, Yasuhiro Fukuma, Rajdeep Singh Rawat, Vasiliki Tileli, Martial Duchamp
Summary: This article discusses the challenges and potential applications of using transmission electron microscopy (TEM) imaging and spectroscopy at low temperatures. The study shows the potential for atomic-resolution imaging at cryogenic temperatures to be generalized to most Li-based materials. Furthermore, real-time TEM imaging in a continuous and variable temperature range has shown promise for studying the evolution of ferroelectric and ferromagnetic domain walls.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Review
Multidisciplinary Sciences
Yonggang Yao, Qi Dong, Alexandra Brozena, Jian Luo, Jianwei Miao, Miaofang Chi, Chao Wang, Ioannis G. Kevrekidis, Zhiyong Jason Ren, Jeffrey Greeley, Guofeng Wang, Abraham Anapolsky, Liangbing Hu
Summary: High-entropy nanoparticles have unique structures and multielemental compositions that offer potential for tunable activity and enhanced stability, but they face challenges from complex atomic structures. The review focuses on discussing important progress in high-entropy nanoparticles and critical needs for their future development.
Article
Multidisciplinary Sciences
Francis Okejiri, Juntian Fan, Zhennan Huang, Kevin Michael Siniard, Miaofang Chi, Felipe Polo-Garzon, Zhenzhen Yang, Sheng Dai
Summary: In this study, a facile synthesis method for single-phase high-entropy oxide nanocrystals was reported, and palladium nanoclusters were successfully stabilized within the structure. The resulting catalyst showed good catalytic performance in CO oxidation, highlighting the advantage of the high-entropy oxide as a carrier support over traditional oxides.
Article
Chemistry, Multidisciplinary
Haoran Yu, Michael J. Zachman, Kimberly S. Reeves, Jae Hyung Park, Nancy N. Kariuki, Leiming Hu, Rangachary Mukundan, Kenneth C. Neyerlin, Deborah J. Myers, David A. Cullen
Summary: Nanoparticles are important materials with unique properties due to their high surface area-to-volume ratio. Scanning transmission electron microscopy (STEM) allows direct visualization of composition and morphology of nanoparticles with atomic precision. However, traditional manual STEM measurements have limitations in sample size, while automated STEM techniques enable high-resolution characterization of nanoparticle properties at sub-micron length scales.
Article
Chemistry, Multidisciplinary
Weiwei Yang, Felipe Polo-Garzon, Hua Zhou, Zhennan Huang, Miaofang Chi, Harry Meyer III, Xinbin Yu, Yuanyuan Li, Zili Wu
Summary: In this study, different Pd single atom catalysts on ceria support were obtained by thermal pretreatment, leading to enhanced activity for methane oxidation. The enhanced activity is related to the oxygen-deficient local structure and elongated interacting distance with ceria.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Environmental
Weiwei Yang, Mi-Young Kim, Felipe Polo-Garzon, Jian Gong, Xiao Jiang, Zhennan Huang, Miaofang Chi, Xinbin Yu, Xiang Wang, Yanbing Guo, Zili Wu
Summary: This study investigates the effects of thermal aging and sulfur poisoning on the efficiency and lifetime of natural gas three-way catalysts (TWCs). The results show that both thermal aging and sulfur-induced deactivations lead to a degradation in CH4 combustion performance due to the reconstruction of Pd species and decreased reducibility of the support. Sulfation aging promotes the activation of CH4 and O2, but the sulfate also hinders the exchange of lattice oxygen.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Raymond Zhang, Timofey Averianov, Ryan Andris, Michael J. Zachman, Ekaterina Pomerantseva
Summary: This study presents the first aqueous exfoliation of chemically prelithiated bilayered vanadium oxide and the vacuum drying process at 200 degrees Celsius provides improved ion storage capacity and electrochemical stability.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Jacob Smith, Zhennan Huang, Wenpei Gao, Guannan Zhang, Miaofang Chi
Summary: Cryogenic four-dimensional scanning transmission electron microscopy (4D-STEM) imaging is a valuable technique for studying quantum materials and their interfaces at atomic scale, but its applications are restricted by the instability of cryo-stages and electronics. To address this issue, an algorithm is developed to correct complex distortions in the atomic resolution cryogenic 4D-STEM data sets. This method involves nonrigid registration and affine transformations to minimize information loss in both reciprocal and real spaces, enabling the reconstruction of sample information from 4D-STEM data sets. It is computationally inexpensive, fast, and suitable for on-the-fly data analysis in future in situ cryogenic 4D-STEM experiments.
Article
Chemistry, Physical
Xinbin Yu, Jisue Moon, Yongqiang Cheng, Luke Daemen, Jue Liu, Sung Wng Kim, Abinash Kumar, Miaofang Chi, Victor Fung, Anibal J. Ramirez-Cuesta, Zili Wu
Summary: NH3 synthesis is a critical industrial process. Ru catalysts have high activity in this reaction but are susceptible to hydrogen poisoning. By using supports like electrides and hydrides, the problem of hydrogen poisoning can be alleviated. However, there is limited research on the structural dynamics of Ru/electride catalysts during the reaction.
CHEMISTRY OF MATERIALS
(2023)
Article
Microscopy
Alex W. W. Robinson, Jack Wells, Daniel Nicholls, Amirafshar Moshtaghpour, Miaofang Chi, Angus I. I. Kirkland, Nigel D. D. Browning
Summary: Interpreting scanning transmission electron microscopy (STEM) images at the atomic scale can be challenging due to various factors affecting contrast. Simulations are often used to validate or interpret experimental images, but they can be time-consuming or require specialized hardware. Recent research in compressive sensing for experimental STEM images has shown that it is possible to reduce the acquired signal and still recover the full image without significant loss of quality. This paper proposes applying similar methods to STEM simulations to increase efficiency.
JOURNAL OF MICROSCOPY
(2023)
Article
Chemistry, Multidisciplinary
Na Yeon Kim, Shaohong Cao, Karren L. More, Andrew R. Lupini, Jianwei Miao, Miaofang Chi
Summary: With the recent development of high-acquisition-speed pixelated detectors, 4D scanning transmission electron microscopy (4D-STEM) has become available in high-resolution electron microscopy. It provides local information on materials that is challenging to extract from bulk techniques and extends conventional STEM imaging. However, the acquisition of 4D-STEM and electron energy loss spectroscopy (EELS) simultaneously is currently not possible due to overlapping detector geometry. This study demonstrates the feasibility of modifying the detector geometry for overcoming this challenge and explores the use of a partial or defective detector for ptychographic structural imaging, enabling simultaneous multi-modal measurements with spectral information added to 4D datasets.
Article
Chemistry, Multidisciplinary
Baraa Werghi, Liheng Wu, Amani M. M. Ebrahim, Miaofang Chi, Haoyang Ni, Matteo Cargnello, Simon R. R. Bare
Summary: The synthesis of well-defined approximate to 2 nm Pt, PtSn, and Pt3Sn nanocrystals with distinct crystallographic phases using colloidal chemistry is reported. The activities and stabilities of hexagonal close packing (hcp) PtSn and face centred cubic (fcc) Pt3Sn are found to be different depending on the hydrogen-rich or poor environment. Fcc Pt3Sn/Al2O3 exhibits a unique phase transformation from fcc phase to L1(2)-ordered superlattice. The study provides fundamental understanding of the structure-performance relationship on emerging bimetallic systems.
Article
Soil Science
Thiago M. Inagaki, Angela R. Possinger, Steffen A. Schweizer, Carsten W. Mueller, Carmen Hoeschen, Michael J. Zachman, Lena F. Kourkoutis, Ingrid Kogel-Knabner, Johannes Lehmann
Summary: The spatial distribution of organic substrates and microscale soil heterogeneity significantly influence organic matter (OM) persistence as constraints on OM accessibility to microorganisms. However, it is unclear how changes in OM spatial heterogeneity driven by factors such as soil depth affect the relative importance of substrate spatial distribution on OM persistence.
SOIL BIOLOGY & BIOCHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Manjeet Chhetri, Mingyu Wan, Zehua Jin, John Yeager, Case Sandor, Conner Rapp, Hui Wang, Sungsik Lee, Cameron J. J. Bodenschatz, Michael J. J. Zachman, Fanglin Che, Ming Yang
Summary: In this study, single-atom Pd and Pt anchored on facet-selective Cu catalysts were used to selectively boost CO2 to CH4 or C2H4 conversion via dual-site pathways, while suppressing the unwanted hydrogen evolution reaction. Copper-based catalysts are capable of catalyzing hydrocarbon formations through electrochemical CO2 reduction. The freedom of catalyst design is limited when alloying copper with platinum group metals due to the risk of hydrogen evolution reaction overriding CO2 reduction. This research successfully achieved targeted enhancement of CO2 reduction while frustrating undesired hydrogen evolution reaction by anchoring atomically dispersed platinum group metal species on both polycrystalline and shape-controlled Cu catalysts. Notably, alloys with small platinum or palladium clusters failed to achieve this objective. With a significant amount of CO-Pd-1 species on copper surfaces, facile CO* hydrogenation to CHO* or CO-CHO* coupling is now viable on Cu(111) or Cu(100) surfaces through Pd-Cu dual-site pathways, selectively producing CH4 or C2H4. This work expands the options for copper alloying in CO2 reduction in aqueous phases.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Haoyang Ni, Zhenyao Wu, Xinyi Wu, Jacob G. Smith, Michael J. Zachman, Jian-min Zuo, Lili Ju, Guannan Zhang, Miaofang Chi
Summary: The atomic configurations of atomically dispersed catalysts (ADCs), such as atom-atom distances and clustering, greatly affect their catalytic performance. This study presents a CNN-based algorithm that can quantify the spatial arrangement of different adatom configurations. The algorithm was proven effective in accurately identifying atom positions and analyzing large data sets of ADCs. It offers a robust method to overcome the bottleneck in STEM analysis for ADC catalyst research and has the potential to be used as an on-the-fly analysis tool for catalysts in future in situ microscopy experiments.
Article
Nanoscience & Nanotechnology
Ounjit Sodpiban, Tanika Kessaratikoon, Jacob Smith, Guodong Ren, Silvano Del Gobbo, Sonali Das, Miaofang Chi, Valerio D'Elia, Bruce C. Gates
Summary: This study prepares atomically dispersed cerium catalysts to enhance their activity in CO oxidation reaction. By using Ce-(III) and Ce-(IV) precursors, the cerium catalysts on MgO support were successfully prepared and characterized before and after catalysis using various techniques. The results show that the excellent catalyst maintains stable activity during the 2-day reaction time and exhibits improved reducibility with the transformation of cerium ions.
ACS APPLIED MATERIALS & INTERFACES
(2023)
