Article
Materials Science, Multidisciplinary
Andrea Droghetti, Ilya Tokatly
Summary: We present first-principles calculations based on density functional theory to estimate the magnitude of current-induced spin polarization (CISP) at the surfaces of 5d transition metals with fcc and bcc crystal structures. Our predictions suggest that W and Ta exhibit the largest surface CISP, while Pt and Au surfaces show considerably weaker CISP. We further discuss the emergence of CISP over a few atomic layers and its differences from the spin accumulation characteristic of the spin Hall effect, which is related to the spin diffusion length of the materials.
Article
Multidisciplinary Sciences
Jingxu Zheng, Yue Deng, Wenzao Li, Jiefu Yin, Patrick J. West, Tian Tang, Xiao Tong, David C. Bock, Shuo Jin, Qing Zhao, Regina Garcia-Mendez, Kenneth J. Takeuchi, Esther S. Takeuchi, Amy C. Marschilok, Lynden A. Archer
Summary: This study investigates the influence of surface chemistry on the reversibility of electrochemical transformations at rechargeable battery electrodes. The results show that a moderate strength of chemical interaction enables the highest reversibility and stability of the plating/stripping redox processes.
Article
Chemistry, Physical
Ziyang Zhang, Liming Liu, Canhui Xu, Shuanglin Hu
Summary: The hydrogen adsorption and diffusion behaviors on clean and doped Zr(0001) surfaces were studied using first-principles calculations. It was found that most dopants promote hydrogen adsorption on next nearest neighbor sites and enhance hydrogen diffusion on the surface plane and penetration into subsurface layers. Element doping may facilitate hydride nucleation in Zr alloys.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Ivan Shtepliuk, Rositsa Yakimova
Summary: This paper discusses the adsorption, diffusion, and intercalation processes of hydrogen and lithium on monolayer epitaxial graphene grown on 4H-SiC, revealing strong and stable chemisorption of hydrogen on the top site of epitaxial graphene and lithiation process occurring via formation of LiC6 phase.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Kaori Seino, Atsushi Oshiyama
Summary: This study conducts first-principles total-energy calculations based on real-space density-functional theory to unveil the atom-scale mechanisms of surface diffusion of adatoms on the Si-faced 3C-SiC(111) stepped surface. The research findings are fundamental in understanding the epitaxial growth mechanisms on SiC surfaces and improving the quality of SiC power devices.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Chemical
Dawei Zhou, Zhuo Wang, Jinbing Cheng, Chunying Pu
Summary: This study identified a high-performance electrode material, a free-standing two-dimensional B2C3P monolayer, through structure prediction and first-principles calculations. The B2C3P monolayer exhibited excellent stability and metallic characteristic, making it a promising anode material for Li-ion batteries with great potential in energy storage devices.
Article
Chemistry, Physical
Dandan Song, Xiaojing Liu, Xiangjian Shen
Summary: In this study, hydrogen interaction with hydrogen-covered Pd(1 0 0) surfaces was investigated using DFT-based microkinetic modeling. Two different mechanisms for hydrogen permeation into the subsurface regions of the hydrogen-covered Pd(1 0 0) surfaces were identified: monomer and dimer pathways. At low coverage, hydrogen-hydrogen interaction significantly increased the adsorption energy and diffusion/permeation barrier. However, the saturated Pd(1 0 0) surface provided a favorable pathway for the formation of subsurface hydrogen species through the dimer permeation pathway. Furthermore, the hydrogen flux through the hydrogen-covered Pd(1 0 0) surfaces exhibited distinct temperature dependence based on the coverage.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Florian Fiesinger, Daniel Gaissmaier, Matthias van den Borg, Timo Jacob
Summary: Rechargeable magnesium-ion batteries show promise as an alternative to commercial lithium-ion batteries due to their safety, environmental friendliness, and higher volumetric capacity. However, the formation of a passivation layer on metallic magnesium electrodes remains a major challenge.
Article
Chemistry, Multidisciplinary
Yibo Wang, Zhenbo Peng, Nianxiang Qiu, Heming He, Rongjian Pan, Lu Wu, Qing Huang, Shiyu Du
Summary: The study investigates the fuel performance of uranium silicide U3Si5 using first-principles methods, revealing that Si-1 atoms are more prone to forming point defects. It predicts the formation of non-stoichiometric U-rich phase of U3Si5 and shows that helium atoms tend to reside in interstitial sites.
Article
Chemistry, Physical
Ruixue Tian, Chaofeng Liu, Guifeng Zhang, Aimin Wu, Man Yao, Hao Huang
Summary: First-principles calculations based on density functional theory were used to systematically investigate the impacts of point defects, including vacancies and antisites, on the Li adsorption and diffusion in monolayer titanium disulfide (TiS2). The results show that defect types strongly influence Li adsorption and diffusion capabilities, with certain defects enhancing adsorption and diffusion rates significantly. This study provides insights for designing high-performance electrode materials for rechargeable batteries.
APPLIED SURFACE SCIENCE
(2021)
Article
Energy & Fuels
Menghang Zhang, Hui Pan, Yigang Wang, Jingui Yang, Hao Dong, Ping He, Haoshen Zhou
Summary: With the growth of the Li-ion battery industry, the global concern over the shortage of lithium (Li) has risen. Extracting Li from the ocean, which holds Li reserves about 16,000 times greater than the current global recoverable Li resources, has become an attractive option. This study used first-principles calculations to evaluate the ion migration barriers and ion selectivity of NASICON-type ion conductors and found that NASICON exhibits remarkable ion selectivity and screening ability, which can be further enhanced through proposed strategies to reduce Li migration energy barrier and improve Li selectivity.
Article
Materials Science, Multidisciplinary
Francesca Fasulo, Arianna Massaro, Ana B. Munoz-Garcia, Michele Pavone
Summary: In this study, the adsorption and insertion of Na+ ions on TiO2 surfaces were investigated under the influence of external electric fields. The results showed that the (001) surface exhibited the highest activity for both directions of electric fields, providing insights for further exploration and design of electrode materials.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Kai Duemmler, Michael Woods, Toni Karlsson, Ruchi Gakhar, Benjamin Beeler
Summary: Molten salts have various applications in nuclear reactor designs and the solar industry, but the transport properties of molten salts at elevated temperatures are not well understood. This study uses ab initio Molecular Dynamics to investigate the transport properties of different molten salt systems. The diffusion coefficient, viscosity, and isochoric heat capacity are compared to experimental and computational data. This is the first study to explore long timescales for the determination of transport properties in molten salts using AIMD.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Physical
Miaogen Chen, Yilian Dai, Taotao Li, Xiaofei Zhang, Can Li, Jing Zhang
Summary: In this work, the possibility of a semi-metallic bilayer boron structure as an anode material for lithium-ion batteries was investigated using first-principles calculations. The results showed that the Li32B88 structure had a theoretical storage capacity of 902 mAh g-1 and an open circuit voltage of 0.18-1.17 V. The material exhibited high structural stability with a small volume change ratio of 0.77% during the lithiation process. Moreover, the indirect diffusion barrier of lithium-ion was 0.47 eV, indicating a fast charge and discharge ability. The theoretical findings suggested that the semi-metallic bilayer borophene could be a potential anode material candidate for lithium-ion batteries.
Article
Chemistry, Multidisciplinary
Jin-Yang Su, Yan-Wei Li, Wei-Hua Wang, Kun Li, Wen Yang
Summary: This study systematically investigates the hydrogen atom capacity in the vacancies of the Li2TiO3 crystal using the first-principles method. The results show that Ti vacancies have the highest hydrogen atom capacity, followed by Li vacancies, while O vacancies have the lowest capacity.
Article
Chemistry, Multidisciplinary
Samuel Bertolini, Timo Jacob
Summary: The study modified the eReaxFF method to allow electrons to modify valence energy, improving the description of the reaction path. By adjusting the methodology when electrons are present, the overall accuracy of the force field and the depiction of angles within molecules were enhanced.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Bjoern Kirchhoff, Christoph Jung, Hannes Jonsson, Donato Fantauzzi, Timo Jacob
Summary: The activity and stability of platinum nanoparticles are influenced by their shape. In this study, a simulation method was used to investigate the oxidation process and behavior of platinum nanoparticles with different shapes, and a relationship between oxidation behavior and surface structure was established.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Laura Braunwarth, Christoph Jung, Timo Jacob
Summary: This study uses molecular dynamics simulations to investigate the structure and dynamics of electrode-electrolyte interfaces, focusing on the Pt(111)/water interface. The results reveal changes in water molecule orientation and intermolecular ordering, challenging previous assumptions about their correlation to free charge density. This work contributes to our understanding of electric double layers and electrochemical processes.
Article
Chemistry, Physical
Jan Niklas Hausmann, Pramod Menezes, Gonela Vijaykumar, Konstantin Laun, Thomas Diemant, Ingo Zebger, Timo Jacob, Matthias Driess, Prashanth W. Menezes
Summary: This article reports a new method of growing hierarchical nanostructures on nickel foam, and successfully doped iron element for oxidation reactions and oxygen evolution reaction. The results show that iron doping is more suitable for oxidation reactions, which can generate higher current density and Faradaic efficiency. In the oxygen evolution reaction, the iron-doped nickel foam electrode can achieve the current density required by industry and maintain stable performance. This article reveals the effects of iron doping and its impact on the reaction mechanism.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Matthias Uhl, Tanja Geng, Philipp A. Schuster, Benjamin W. Schick, Matthias Kruck, Alexander Fuoss, Alexander J. C. Kuehne, Timo Jacob
Summary: By replacing the electrolyte with a deep eutectic solvent and using a polymer as the electrode, an all-organic battery can be achieved. The combination of different solvents and salt concentrations affects the stability and viscosity of the battery. The eutectic mixture with a 1:6 ratio offers the best balance between stability and viscosity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Evelyn Artmann, Lukas Forschner, Konstantin M. Schuettler, Mohammad Al-Shakran, Timo Jacob, Albert K. Engstfeld
Summary: Researchers propose a simple method for the preparation of nanoporous gold films, which can be achieved by high voltage electrolysis or anodic contact glow discharge electrolysis. The structural properties of the resulting films can be controlled by adjusting the electrolysis conditions and the reduction reaction conditions.
Article
Chemistry, Multidisciplinary
Florian Fiesinger, Daniel Gaissmaier, Matthias van den Borg, Julian Bessner, Adri C. T. van Duin, Timo Jacob
Summary: One of the key challenges in the development of magnesium-ion batteries (MIB) is the formation of a passivating boundary layer at the magnesium anode. A Mg/O ReaxFF parameter set was developed to accurately model the degradation process of the magnesium anode by O-2 impurities. It was found that O-2 immediately dissociates upon first contact with the magnesium anode, leading to high temperatures and further oxidation. The trained force field can be used to study reactions in Mg-air batteries and the oxidation of magnesium metal in general.
Article
Electrochemistry
Daniel Rutz, Ingolf Bauer, Felix Brauchle, Timo Jacob
Summary: In this study, user-defined reference electrodes based on LFP were fabricated using an ultrashort pulse laser. The results showed that these electrodes have minimal impact on the cell capacity and can provide reproducible voltage output at low to moderate C-rates. They also do not affect the cell expansion during cycling.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Julia Bord, Bjoern Kirchhoff, Matthias Baldofski, Christoph Jung, Timo Jacob
Summary: Density functional theory (DFT) is utilized to investigate the electronic structure of platinum clusters on different graphene substrates. The size and defects of both the clusters and the graphene substrates are examined. The results reveal that larger vacancies lead to stronger binding of Pt clusters, while defect-free graphene shows more exothermic formation energy with increasing cluster size. Oxygen-free graphene supports are crucial for successful attachment of Pt, and cluster stability depends on the number and ratio of Pt-C, Pt-Pt, and Pt-O bonds rather than the cluster geometry.
Article
Chemistry, Physical
Hongyuan Yang, Pramod V. Menezes, Guoliang Dai, Gonela Vijaykumar, Ziliang Chen, Mohammad Al-Shakran, Timo Jacob, Matthias Driess, Prashanth W. Menezes
Summary: Developing bifunctional electrodes for oxidation catalysis is highly desirable for hydrogen and value-added chemicals production. Here, we directly activate the nickel foam through the incorporation of elemental P (P-NF) using a facile, controllable, and ultrafast in-liquid plasma electrolysis approach. The practical bifunctionality of P-NF is additionally verified with selective oxygenation of organics forming value-added chemicals.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Changbin Im, Bjorn Kirchhoff, Igor Krivtsov, Dariusz Mitoraj, Radim Beranek, Timo Jacob
Summary: Computational investigation of PCN materials can lead to better understanding and optimization strategies. Thermochemical calculations predict stable structural motifs and show that condensed PCN domains in a less condensed framework can have desirable optical properties.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Lukas Forschner, Evelyn Artmann, Timo Jacob, Albert K. Engstfeld
Summary: Applying an external potential difference between two electrodes leads to a voltage drop in an ion conducting electrolyte. The electrolyte potential is relevant in electrochemistry and various applications such as bipolar electrochemistry, ohmic microscopy, or contact glow discharge electrolysis. This study focuses on the electrolyte potential during high voltage electrolysis in an electrolysis cell using reversible hydrogen electrodes as reference electrodes. A computational COMSOL model is used to support the experimental findings, and the influence of cell geometry on the electrolyte potentials is evaluated. The amount of oxide formed during high voltage electrolysis is found to be related to the current rather than the applied voltage, based on the knowledge of potential distribution.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Review
Chemistry, Physical
Bjoern Kirchhoff, Christoph Jung, Daniel Gaissmaier, Laura Braunwarth, Donato Fantauzzi, Timo Jacob
Summary: Nanoparticles (NPs) as heterogeneous catalysts have large active surface area and size-dependent catalytic properties. The ability to computationally predict the most favorable NP structures for catalytic reactions is important for material optimization. However, simulations of NP model systems present unique challenges to computational scientists and require different data analysis strategies compared to simulations of single crystal surface models. This work aims to review analytical methods and data analysis strategies for extracting thermodynamic trends from NP simulations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
