Article
Chemistry, Multidisciplinary
Yao Yang, Inwhan Roh, Sheena Louisia, Chubai Chen, Jianbo Jin, Sunmoon Yu, Miquel B. Salmeron, Cheng Wang, Peidong Yang
Summary: Understanding the chemical environment and interparticle dynamics of nanoparticle electrocatalysts is crucial for controlling their activity and selectivity. In this study, the EC-RSoXS method was used to investigate the structural transformation and chemical identity of active sites in Cu nanoparticle ensembles. The results revealed different behaviors of nanoparticles of different sizes under X-ray exposure.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Xing Huang, Travis Jones, Alexey Fedorov, Ramzi Farra, Christophe Coperet, Robert Schloegl, Marc-Georg Willinger
Summary: Metal catalysts play a crucial role in industrial redox reactions, but the state and active sites of these catalysts under operating conditions are largely unknown. This study uses operando transmission electron microscopy to interrelate the structural dynamics of redox metal catalysts to their activity, revealing the importance of chemical dynamics in driving surface phase transitions and forming transient active sites during catalysis. Density functional theory calculations show that chemical dynamics play a key role in driving structural transformations even far from thermodynamic equilibrium.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Bas Terlingen, Ramon Oord, Mathieu Ahr, Eline Hutter, Coert van Lare, Bert M. Weckhuysen
Summary: The commercialization of CH4 valorization processes is currently hindered by the lack of suitable catalysts. Lanthanide-based catalysts, especially EuOCl, show promising catalytic activity and selectivity in the oxychlorination of CH4. Increasing the HCl concentration can enhance the catalytic performance, making EuOCl a potential candidate for economically viable CH4 valorization process.
Review
Chemistry, Multidisciplinary
Sam Benson, Fabio de Moliner, William Tipping, Marc Vendrell
Summary: Recent progress in optical bioimaging has led to the demand for minimal chemical reporters that can preserve the properties and activities of biomolecules. Various approaches have been developed to reduce the size of fluorescent and Raman labels to a few atoms and incorporate them into building blocks to form native-like supramolecular structures. This integration of small optical reporters into biomolecules has enabled the creation of previously inaccessible smart molecular entities, greatly expanding their applications in biological imaging.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Analytical
Hongwei Yang, Yayun Wu, Hefei Ruan, Feng Guo, Yuxin Liang, Gege Qin, Xiaolong Liu, Zhen Zhang, Jinghe Yuan, Xiaohong Fang
Summary: This study introduces a new type of surface-engineered gold nanoclusters (Au NCs) for super-resolution imaging, which are ultrasmall and ultrabright. With modification on the surface, the fluorescence intensity of Au NCs is enhanced and specific biomolecules can be labeled. These Au NCs show excellent performance and have great potential for applications in STED and DLEM imaging.
ANALYTICAL CHEMISTRY
(2022)
Article
Optics
Yingwen Zhang, Duncan England, Benjamin Sussman
Summary: This article presents a snapshot hyperspectral imaging technique that utilizes quantum ghost spectroscopy, allowing high spectral resolution without sacrificing spatial resolution and improving resource efficiency.
Article
Electrochemistry
Po-Hsiu Chien, Xianyang Wu, Bohang Song, Zhijie Yang, Crystal K. Waters, Michelle S. Everett, Feng Lin, Zhijia Du, Jue Liu
Summary: LNO represents the end member in the cathode system, with high theoretical specific capacity but suffers from phase transitions and unfavorable reactions during electrochemical cycling. The anomalous increase or decrease of Ni-O (Li-O) bond length in the H3 phase at high SOC is discussed in the context of O2- (2p)-> Ni4+ (3d) negative charge transfer.
BATTERIES & SUPERCAPS
(2021)
Article
Chemistry, Physical
Daren Wu, Steven T. T. King, Nahian Sadique, Lu Ma, Steven N. N. Ehrlich, Sanjit Ghose, Jianming Bai, Hui Zhong, Shan Yan, David C. C. Bock, Esther S. S. Takeuchi, Amy C. C. Marschilok, Lisa M. M. Housel, Lei Wang, Kenneth J. J. Takeuchi
Summary: In this study, operando synchrotron X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) were used to investigate the mechanism of aqueous Zn/α-MnO2 batteries with ZnSO4 electrolyte. A multi-stage Mn dissolution-conversion charge storage mechanism was revealed, involving reversible solid-aqueous phase transformation and solid redox mechanism. The findings provide a detailed charge storage mechanism for aqueous Zn/α-MnO2 batteries and can guide future studies on improving their reversibility and stability.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Jared J. Lodico, Matthew Mecklenburg, Ho Leung Chan, Yueyun Chen, Xin Yi Ling, B. C. Regan
Summary: By using electron energy-loss spectroscopy (EELS) technique in a scanning transmission electron microscope (STEM), we demonstrate operando spectrum imaging of a Li-ion battery anode, allowing us to observe the constituents and structures of the solid-electrolyte interphase (SEI) layer. This provides insights into the complex mechanisms affecting battery safety, capacity, and lifetime.
Article
Chemistry, Multidisciplinary
Alexandre C. Foucher, Nicholas Marcella, Jennifer D. Lee, Daniel J. Rosen, Ryan Tappero, Christopher B. Murray, Anatoly Frenkel, Eric A. Stach
Summary: This study investigates the characteristics of Co2Pt3 nanoparticles during a redox cycle using in situ methods, revealing the segregation of cobalt in the particles and significant changes in the oxidation state of cobalt. Understanding the dynamical restructuring effects in CoPt nanocatalysts at the atomic scale is crucial for improving catalyst design in major chemical processes.
Article
Chemistry, Analytical
Oren Katz, Travis Ferguson, Emma Abbey, Sarah-Johanna Klose, Chris Prufert, Hans-Peter Loock
Summary: This article presents a 4-dimensional fluorescence imaging system that includes an excitation-emission-matrix spectrum with 31 excitation wavelengths and 8 emission wavelengths for each of the 65,536 pixels in the image array. The use of Hadamard-transform multiplexing and a programmable light source allows for high-speed data acquisition. The system is demonstrated and characterized using various dye solutions and their mixtures, as well as fluorescent dye solutions with changing fluorescence as a function of temperature. Multivariate analysis is applied to generate images of the spatial distribution of the fluorophores and their intensity over time.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Rhianna J. Rowland, Yurong Chen, Imogen Breen, Liang Wu, Wendy A. Offen, Thomas J. Beenakker, Qin Su, Adrianus M. C. H. van den Nieuwendijk, Johannes M. F. G. Aerts, Marta Artola, Herman S. Overkleeft, Gideon J. Davies
Summary: The study synthesized a series of cyclophellitol epoxide and aziridine inhibitors and activity-based probes, revealing their binding modes with GBA and potential applications in GD treatment. A bi-functional aziridine ABP may serve as a more powerful imaging agent, but did not achieve additional benefits over the first generation ABPs.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Dengfeng Cao, Daobin Liu, Shuangming Chen, Oyawale Adetunji Moses, Xingjia Chen, Wenjie Xu, Chuanqiang Wu, Lirong Zheng, Shengqi Chu, Hongliang Jiang, Changda Wang, Binghui Ge, Xiaojun Wu, Jing Zhang, Li Song
Summary: This study presents a cobalt sulfide catalyst with chameleon-like structural self-optimization during the oxygen evolution reaction under neutral and alkaline conditions, activating distinct catalytic sites and achieving high catalytic activity. The findings shed light on the essence of the structural self-optimization process of catalysts and provide new insights for future OER relevant studies and chemistry and catalysis fields.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Physics, Applied
Kosuke Suzuki, Shunta Suzuki, Yuji Otsuka, Naruki Tsuji, Kirsi Jalkanen, Jari Koskinen, Kazushi Hoshi, Ari-Pekka Honkanen, Hasnain Hafiz, Yoshiharu Sakurai, Mika Kanninen, Simo Huotari, Arun Bansil, Hiroshi Sakurai, Bernardo Barbiellini
Summary: Using high-energy synchrotron x rays for Compton scattering imaging allows visualization of lithiation state in lithium-ion batteries, revealing inhomogeneous patterns and oscillations during charge-discharge cycles.
APPLIED PHYSICS LETTERS
(2021)
Review
Chemistry, Multidisciplinary
Elena Groppo, Sergio Rojas-Buzo, Silvia Bordiga
Summary: Operando IR spectroscopy is a crucial characterization method for studying heterogeneous catalysts under reaction conditions. This review emphasizes the importance of IR spectroscopy by discussing selected case studies that demonstrate its ability to provide relevant information in this field.
Article
Chemistry, Multidisciplinary
James P. Horwath, Colin Lehman-Chong, Aleksandra Vojvodic, Eric A. Stach
Summary: The surface morphology of heterogeneous catalysts, consisting of supported metallic nanoparticles, plays a crucial role in catalytic activity, selectivity, and degradation rates. However, research on the link between nanoparticle surface structures and degradation rates or mechanisms is limited. In this study, a combination of experimental observations and computational techniques is used to establish an atomistic understanding of how variations in surface structures and atomic coordination environments lead to shifting evolution mechanisms as a function of temperature. The findings reveal a two-step evolution mechanism and provide insights into why sublimation rates vary between nanoparticles in a system of nearly identical particles.
Article
Physics, Applied
Jeffrey X. Zheng, Merrilyn Mercy Adzo Fiagbenu, Giovanni Esteves, Pariasadat Musavigharavi, Akhil Gunda, Deep Jariwala, Eric A. Stach, Roy H. Olsson
Summary: Ferroelectric Al1-xScxN is of interest for its unique ferroelectric properties and compatibility with metal oxide semiconductor back-end-of-line processing. However, for applications in embedded nonvolatile memory, a lower switching voltage is desired. This study demonstrates that reducing the thickness of Al0.72Sc0.28N films can decrease the coercive field and increase the breakdown field. A 5.4nm film showed ferroelectric switching at 5.5V and a switching speed of 60 ns when excited with a 500 ns pulse.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Alexandre C. Foucher, Daniel J. Rosen, Shengsong Yang, Dario Ferreira Sanchez, Ilia Sadykov, Daniel Grolimund, Anatoly I. Frenkel, Christopher B. Murray, Eric A. Stach
Summary: This article presents the characterization and applications of core-shell Cu-Ir nanocatalysts in oxygen reduction reaction and oxygen evolution reaction. By controlling the thickness of the Ir shell, the Cu core can be removed via oxidation to obtain Ir shells, which determine the stability and optimization of the precious metals. Through in situ scanning transmission electron microscopy, the remarkable stability of the Ir shells at high temperatures under oxidative and reductive environments is demonstrated. Electrochemical measurements show that the Cu-Ir nanocatalysts exhibit promising activity and stability compared to a commercial catalyst. Thin Ir shells result in higher surface area per gram of Ir and higher activity, while thicker Ir shells are more stable and exhibit excellent electrochemical properties in aqueous and alkaline environments. Consequently, Ir nanoshells are considered interesting candidates for reducing the cost of catalysis and improving chemical performance in fuel cells.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Junying Li, Peipei Huang, Facheng Guo, Jiahao Huang, Shuting Xiang, Ke Yang, N. Aaron Deskins, Victor S. Batista, Gonghu Li, Anatoly I. Frenkel
Summary: In this study, the structure of a hybrid photocatalyst consisting of a macrocyclic cobalt complex deposited on graphitic carbon nitride (C3N4) was investigated using XANES, EXAFS spectroscopies, DFT, and computational XANES modeling. The results revealed that the cobalt complex binds to C3N4 through surface OH or NH2 groups. By refining the local geometry and binding sites, this research provides an important benchmark for modeling a large class of molecular catalysts and enables further improvement through chemometrics-based approaches and machine learning methods of XANES data analysis.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Physics, Applied
Yunfei He, Shangyi Chen, Merrilyn Mercy Adzo Fiagbenu, Chloe Leblanc, Pariasadat Musavigharavi, Gwangwoo Kim, Xingyu Du, Jiazheng Chen, Xiwen Liu, Eric A. Stach, Roy H. Olsson, Deep Jariwala
Summary: This letter presents the oriented growth and switching of thin ferroelectric aluminum scandium nitride (AlScN) films directly on degenerately doped 4H silicon carbide (SiC) wafers. The high-quality thin Al0.68Sc0.32N films on doped SiC substrates enable the monolithic integration of nonvolatile memory with SiC-based logic devices suitable for high temperature operation as well as high-power switching, memory, and sensing applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Merrilyn M. A. Izhar, Merrilyn M. A. Fiagbenu, Pariasadat Musavigharavi, Xingyu Du, Jeff Leathersich, Craig Moe, Abhay A. Kochhar, Eric A. Stach, Ramakrishna H. Vetury, Roy H. Olsson
Summary: This letter presents a K-band bulk acoustic wave (BAW) resonator constructed from an Al0.72Sc0.28 N periodically poled piezoelectric film. The resonators exhibited dominant resonance responses around 20 GHz, approximately four times higher than the resonance frequencies of similar unpoled devices fabricated on the same wafer. Resonators with a quality factor (Q(p)) of 160 and an electromechanical coupling (k(t)(2)) of 8.23% were achieved. The figure of merits (defined as FoM(I) = k(t)(2) Q(p) and FoM(II) = f(p)FoM(I) x 10(-9)) of the resonator are 13.2 and 274 which are higher than most reported acoustic resonators operating at K-band (18 GHz to 27 GHz) or higher frequency. The experimental results suggest that periodically poled BAW resonators are promising for emerging RF filter and oscillator applications at K-band frequencies.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Chemistry, Physical
Kai Shen, Jian Chang, Rajeev Kumar Rai, Ching-Yu Wang, Eric A. Stach, Raymond J. Gorte, John M. Vohs
Summary: The thermodynamic and structural properties of 1 nm thick films of CeVO4 and LaVO4 supported on & gamma;-Al2O3 were compared to the corresponding bulk rare-earth vanadates. The thin films exhibited different crystalline structures and equilibrium oxygen pressures compared to the bulk materials. Thin-film LaVO4 showed reversible transitions between perovskite and monazite structures, while thin-film CeVO4 showed reversible transitions between perovskite and fluorite structures. The reasons for these differences were discussed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Xiaoman Zhang, Eric A. Stach, W. J. Meng, Andrew C. Meng
Summary: In this study, epitaxial wurtzite AlScN thin films were grown on Si (111) substrates by ultra-high vacuum reactive sputtering. Sc alloying in AlN enhances piezoelectricity and induces ferroelectricity, making epitaxial thin films suitable for systematic investigations of these materials. Increasing Sc concentration leads to crystalline disorder and a structural transition from wurtzite to rocksalt, as well as nanoscale compositional segregation consistent with spinodal decomposition. The observed composition fluctuations are correlated with polarization domains, suggesting an influence on ferroelectric properties. These results provide a route for creating single crystal AlScN films and self-assembled composition modulation.
NANOSCALE HORIZONS
(2023)
Article
Chemistry, Multidisciplinary
Haodong Wang, Ryuichi Shimogawa, Lihua Zhang, Lu Ma, Steven N. Ehrlich, Nebojsa Marinkovic, Yuanyuan Li, Anatoly I. Frenkel
Summary: Single-atom catalysts are sensitive to external conditions, and tracking their structural evolution can identify active species and active sites. The migration of platinum nanoparticles affects catalytic activity.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Physical
Scott C. McGuire, Nathaniel R. Hurley, Michael G. Gallagher, Lihua Zhang, Anatoly I. Frenkel, Stanislaus S. Wong
Summary: In the development of novel fuel cell catalysts, we have synthesized ultrathin nanowires and spoke-like dendritic clusters. Analysis shows that the elements tend to segregate into clusters, and the specific activity values of the samples in methanol oxidation reaction correlate with their chemical composition and reaction process.
Article
Multidisciplinary Sciences
Maxim Varenik, Boyuan Xu, Junying Li, Elad Gaver, Ellen Wachtel, David Ehre, Prahlad K. Routh, Sergey Khodorov, Anatoly I. Frenkel, Yue Qi, Igor Lubomirsky
Summary: In this study, a low relative permittivity ceramic material ZrxCe1-xO2 with electromechanical properties comparable to the best performing electrostrictors was discovered. The electromechanical properties of ZrxCe1-xO2 are enabled by elastic dipoles formed under an applied anisotropic electric field, which distinguishes it from other materials.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yuanyuan Li, Haodong Wang, Haohong Song, Ning Rui, Matthew Kottwitz, Sanjaya D. Senanayake, Ralph G. Nuzzo, Zili Wu, De-en Jiang, Anatoly I. Frenkel
Summary: This study successfully improved the activity of CO oxidation by designing Pt single atom catalysts supported on Gd-doped ceria. The results showed that a new Pt single atom site formed under CO pretreatment at elevated temperatures can significantly reduce the energy barrier of CO oxidation. The reactivity and reaction mechanism of the catalyst can be tuned by changing the local electronic and atomic structure of the Pt single atom through Gd doping.
Article
Chemistry, Multidisciplinary
Yikang Yu, Hyeongjun Koh, Zisheng Zhang, Zhenzhen Yang, Anastassia N. Alexandrova, Mangilal Agarwal, Eric A. Stach, Jian Xie
Summary: The study challenges the traditional understanding of lithium ion transport in the solid electrolyte interphase (SEI) and proposes a new mechanism of one-step pore diffusion. The results suggest that the influence of SEI structure on lithium ion transport kinetics is less significant than previously believed. This finding has potential implications for the design of fast-charging battery materials.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Ingrid J. Paredes, Amani M. Ebrahim, Rito Yanagi, Anna M. Plonka, Shuzhen Chen, Hanlu Xia, Scott Lee, Mersal Khwaja, Haripriya Kannan, Ajay Singh, Sooyeon Hwang, Anatoly I. Frenkel, Ayaskanta Sahu
Summary: The chemical versatility and rich phase behavior of tin phosphides have attracted researchers' interest for various applications. However, there are few viable methods to obtain high-quality and phase-controlled tin phosphides. In this study, we demonstrated that inexpensive and commercially available aminophosphines can be used to synthesize different phases of tin phosphides. We manipulated various factors to obtain phase-pure Sn3P4, SnP, and Sn4P3 nanocrystals. The phase purity was confirmed by X-ray diffraction and transmission electron microscopy.
MATERIALS ADVANCES
(2023)
