Article
Materials Science, Multidisciplinary
Min Huang, Songtao Wu
Summary: Density Functional Theory calculations show that the diffusivity of Co adatoms on Cu-Al(111) is lower compared to Cu(111), which can suppress the agglomeration of Co atoms. Co islands deposited on Cu-Al(111) covered with Co films tend to grow layer-by-layer, indicating perfect wetting of Cu-Al(111) by Co.
Article
Chemistry, Physical
Cameron J. Owen, Stephen J. Jenkins
Summary: The study focuses on the adsorption behavior of single-atom catalysts on CeO2 surfaces, using gold catalysts as a reference. The results help to understand the performance of oxide-supported single-atom catalysts.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Wahyu Tri Cahyanto, Siti Zulaehah, Wahyu Widanarto, Farzand Abdullatif, Mukhtar Effendi, Hideaki Kasai
Summary: A theoretical study based on density functional theory investigated the H2O dissociation reaction on the Pt(111) metal surface alloyed with Ru and Mo, revealing that the reaction requires almost no energy cost and is both kinetically favored and thermodynamically neutral. The electronic structure analysis showed that Mo releases more charge to bind the adsorbed hydroxyl, leading to the stabilization of the OH-surface bond. This stability is believed to be a key factor in the almost spontaneous dissociation process of H2O.
Article
Chemistry, Physical
Reihan Nejatipour, Mehrdad Dadsetani
Summary: Using density functional theory and ELNES analysis, this study calculates and describes the sulfur K and L2,3 edge spectra of mercury-based defective chalcopyrites and its spinel structure, and compares with existing experimental spectra. Substituting gallium with aluminium alters the sulfur edge ELNES, reducing relative spectral intensities and shifting main peaks to higher energies. Covalency power and bond length contribute significantly to the dispersion of the edge spectra.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Agnes M. Samuel, Ehab Samuel, Victor Songmene, Fawzy H. Samuel
Summary: The present article investigates the relationship between solidification parameters and the macrostructure and microstructure. The results show that undercooling and recalescence temperatures increase with the initial increase in titanium concentration, but rapidly decrease at approximately 0.25%. The temperatures then increase again with further increase in Ti concentration. The grain size decreases with Ti concentration, reaching a minimum at around 0.20%. The interaction between the grain refiner and traces of other metals in the base alloy is also important in determining the grain refinement mechanism.
Article
Materials Science, Multidisciplinary
Shuang Zhang, Dongjun He, Ping Huang, Fei Wang
Summary: This study observed unexpectedly large periodic moire patterns with a period of approximately 8.9 nm at the graphene/Al (111) interface for the first time. The moire pattern periodicity with respect to rotation orientation angle was evaluated by theoretical calculation, and the formation process was investigated via molecular dynamics simulations. The study proposed that thermal stress stimulated interface rotational growth may play a dominating role in the formation of the moire pattern.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Physical
Mahdieh Mozaffari Majd, Hossein Farrokhpour, Alireza Najafi Chermahini, Hossein A. Dabbagh
Summary: This study investigated the chiral discrimination ability of different cyclic peptides towards enantiomers of phenylalanine theoretically, and found that 8mcyc and 9mcyc exhibited the highest discrimination ability in the gas phase and water, respectively. Additionally, natural bonding orbital calculations were performed to determine the presence and strength of hydrogen bonds between enantiomers and cyclic peptides.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Multidisciplinary Sciences
Earl Matthew Davis, Arno Bergmann, Chao Zhan, Helmut Kuhlenbeck, Beatriz Roldan Cuenya
Summary: Water electrolysis using renewable energy to produce 'green H-2' is a promising option for the future green economy. However, the efficiency is limited by the slow and complex oxygen evolution reaction at the anode. Cobalt-based oxidic anodes with added iron have been found to be good electrocatalysts for this reaction, but the role of iron is still unclear. In this study, the authors compare the oxygen evolution reaction activity of three well-defined epitaxial thin-film electrodes to investigate the role of iron.
NATURE COMMUNICATIONS
(2023)
Article
Spectroscopy
Sumalya Kaluva, Venkata Lakshmi Karri, Bhagwat Kharat, Mahadevappa Naganathappa
Summary: The present study investigates the analysis and characterization of linear and cyclic diazene oligomers in gas and water solvent states. Spectroscopic techniques such as geometrical parameters, infrared spectra, electronic absorption spectra, and natural transition orbitals (NTOs) are used to study these oligomers. Many-body analysis techniques are implemented to examine the interactions among the diazene oligomers using B3LYP exchange and correlation functional and 6-311++G (d,p) basis set. Significant changes in vibrational modes are observed when transitioning from gas phase to water solvent phase. The electronic absorption spectra, wavelength of electronic transitions, oscillator strength, and HOMO to LUMO gap are calculated using time-dependent density functional theory (TD-DFT).
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Materials Science, Multidisciplinary
Mandana Safari, Erik Vesselli, Stefano de Gironcoli, Stefano Baroni
Summary: The translation from a metal substrate stabilizes honeycomb borophene and the impact of oxygen on the strength of the coupling between the substrate and overlayer is investigated in this theoretical study. The results suggest that oxygen doping reduces charge transfer between aluminum and borophene, allowing modulation of their strength and potential engineering of the electronic properties of 2D-supported borophene sheets for industrial applications.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
E. E. Hernandez-Vazquez, S. Lopez-Moreno, F. Munoz, J. L. Ricardo-Chavez, J. L. Moran-Lopez
Summary: Theoretical study on the adsorption of Mn trimer on Au(111) and Cu(111) surfaces was conducted. The lowest energy configuration for the trimer on both metals was found to be the AF(Delta) configuration, forming an isosceles triangle.
Article
Chemistry, Physical
Rishabh Kumar Pandey, Korutla Srikanth, Anuj Tak, Abhishek Kumar, Tammineni Rajagopala Rao
Summary: This study focuses on the non-adiabatic effects in the photoelectron spectra of Al6N-. It performs ab initio electronic structure calculations for the first seven low-lying electronic states of Al6N- and conducts a nuclear dynamics study using time-dependent and time-independent quantum chemistry methods. A diabatic electronic representation is used to construct a model vibronic Hamiltonian and estimate the coupling parameters for the fifteen vibrational modes of Al6N-. Theoretical spectral bands are obtained using vibronic coupling theory and reduced dimensional calculations to understand the contribution of individual vibrational modes to the overall photoelectron spectra. The theoretically obtained photodetachment spectra show good agreement with the experimental spectra, indicating vibronic coupling between closely spaced spectral bands.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Qi Yang, Ruixuan Xu, Hongqi Nie, Qilong Yan, Jun Liu, Jiuyu Chen, Yunlan Sun
Summary: The adsorption and decomposition processes of ammonium perchlorate (AP) on pure-Al and Al2O3/Al surfaces were investigated using density functional theory. The results showed that the pure-Al surface is more conducive to the decomposition of AP and the activation of NH3, while the Al2O3/Al surface promotes the disengagement of H and NH3 decomposition.
MOLECULAR CATALYSIS
(2024)
Article
Spectroscopy
Xiangrong Li, Ruonan Xu, Zeqing Cheng, Zhizhi Song, Ziyang Wang, Hanxiao Duan, Xinzhe Wu, Tianjun Ni
Summary: This study suggests that flavonoids bind to hyaluronidase and inhibit its activity, demonstrating anti-inflammatory effects. The binding affinity of flavonoids to hyaluronidase decreases in the order of rutin, hesperidin, myricetin, puerarin, genistein, and naringin.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2021)
Article
Chemistry, Physical
Dongliang Liu, Erum Pervaiz, Samira Adimi, Tiju Thomas, Fengdong Qu, Chaozhu Huang, Rui Wang, Heng Jiang, Minghui Yang
Summary: The study found that the decorated W atom in direct vicinity of pre-adsorbed oxygen is the best site for acetone adsorption on the W-Co3O4 (111) surface. This modification of the W atom leads to a narrower energy band gap, altered electronic properties, and increased number of transferred electrons.
APPLIED SURFACE SCIENCE
(2021)
Review
Chemistry, Multidisciplinary
Axel Gross, Sung Sakong
Summary: Structures and processes at water/metal interfaces are crucial for electrochemical energy conversion and storage, photoconversion, sensors, and corrosion. They also provide a model system for studying solid-liquid interfaces, combining concepts from chemistry and physics. The interactions between water-water and water-metal are similar in strength, resulting in a competition for the structures at water/metal interfaces. Ab initio molecular dynamics simulations are the preferred method for modeling these interfaces, but they require substantial computational resources.
Article
Chemistry, Physical
Naoum C. Bacalis, Zhuang Xiong, Zhen Xin Wang, Dimitris Karaoulanis
Summary: The article discusses a functional called omega n that is able to locate excited state and saddle points in chemical reactions. It is applicable to large systems and can be treated by reducing it to a self-consistent generalized eigenvalue problem.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2022)
Article
Chemistry, Physical
Luis A. Mancera, Thomas Diemant, Axel Gross, R. Juergen Behm
Summary: This study investigates the adsorption behavior of hydrogen on PdAg/Pd(111) surface alloys, aiming to understand the effects of adsorption energy on the Pd content. The results show that specific mono- and bimetallic adsorption sites and ensembles play a crucial role in the changes of adsorption energy. The comparison with previous findings provides a better understanding of the catalytic reactions on bimetallic catalysts.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Mohsen Sotoudeh, Manuel Dillenz, Johannes Doehn, Julian Hansen, Sonia Dsoke, Axel Gross
Summary: Through theoretical and experimental research, we have identified cathode materials with improved Mg-ion mobility, which is significant for the utilization of Mg-metal batteries.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Jun Huang, Yufan Zhang, Mengru Li, Axel Gross, Sung Sakong
Summary: The theoretical modeling of metal/water interfaces focuses on the configuration of the electric double layer (EDL) under grand canonical conditions. Ab initio molecular dynamics (AIMD) simulations are ideal for treating water-metal interactions but are limited by small ensembles and short simulation times. Semiclassical approaches can efficiently handle the EDL model by averaging microscopic details. By combining AIMD and semiclassical methods, an improved description of the EDL can be obtained. Comparing these approaches using the Pt(111)/water interface, we analyze the differences in electric field, water configuration, and double-layer capacitance, and discuss their contributions to EDL theory.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Tao Zhang, Mohsen Sotoudeh, Axel Gross, Robert M. McMeeking, Marc Kamlah
Summary: The cathode material NaxFePO4 of sodium-ion batteries exhibits complex phase segregation thermodynamics and large volume change during (dis)charging. A virtual multiscale modeling chain is established to construct a 3D anisotropic electro-chemo-mechanical phase-field model based on first-principles calculations for NaxFePO4, which considers various factors such as phase changes, electrochemical reactions, anisotropic diffusion, anisotropic misfit strain, and anisotropic elasticity. The study investigates the influence of surface reaction kinetics and crystal anisotropy on the microstructure evolution of NaxFePO4 particles and provides insights into engineering desired phase behavior with better mechanical stability.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
Daniel Stottmeister, Axel Gross
Summary: The transition from lithium-based energy storage to post lithium systems is crucial for achieving environmentally sustainable energy infrastructure. Sodium and potassium batteries are prime candidates for replacing lithium. However, the formation process of the solid electrolyte interphase (SEI) for Na and K batteries is not well-understood compared to lithium systems. In this study, ab initio molecular dynamics simulations are used to investigate the initial steps of SEI formation on lithium, sodium, and potassium metal anodes. The results show that carbon monoxide and alkali-carbonate are the dominant products during the early SEI formation of cyclical carbonates on alkali metal anodes.
BATTERIES & SUPERCAPS
(2023)
Article
Chemistry, Multidisciplinary
Daniel Stottmeister, Leonie Wildersinn, Julia Maibach, Andreas Hofmann, Fabian Jeschull, Axel Gross
Summary: The increasing demand for electrochemical energy storage has led to the development of post-lithium battery systems. Sodium-based batteries are among the most promising new battery types. However, similar to lithium batteries, sodium batteries face issues such as parasitic side reactions and an unstable solid electrolyte interface (SEI). This study investigates the formation of SEI on sodium metal and reveals the crucial role of a sodium chloride layer in the formation of propylene oxide.
Article
Chemistry, Physical
Majid Rezaei, Sung Sakong, Axel Gross
Summary: Accurate modeling of highly concentrated aqueous solutions, such as WiS electrolytes, requires proper consideration of polarization contributions. This study analyzes different approaches to include polarization effects in MD simulations and identifies an efficient combination of force fields for Na-OTF solution: a Drude polarizable force field for salt ions and non-polarizable models for water. This cost-effective combination ensures simulation stability and reproduces a broad range of electrolyte properties.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Electrochemistry
Katrin Forster-Tonigold, Florian Buchner, Axel Gross, R. Juergen Behm
Summary: By utilizing surface chemistry experiments and DFT calculations, this study investigates the initial stages of SEI formation in Na ion or Na metal batteries. The results reveal the interactions and reactions between a Na surface and the ionic liquid, leading to the formation of larger TFSI-based fragments and atomic adsorbates at the Na surface.
BATTERIES & SUPERCAPS
(2023)
Review
Chemistry, Physical
Mohsen Sotoudeh, Sebastian Baumgart, Manuel Dillenz, Johannes Doehn, Katrin Forster-Tonigold, Katharina Helmbrecht, Daniel Stottmeister, Axel Gross
Summary: Ion mobility is a critical performance parameter in electrochemical devices. This review discusses the chemical trends in ion mobility in crystalline materials and the nature of the migrating species.
ADVANCED ENERGY MATERIALS
(2023)
Article
Electrochemistry
Manuel Dillenz, Mohsen Sotoudeh, Clarissa Glaser, Juergen Janek, Axel Gross, Holger Euchner
Summary: Spinel-type materials with high Mg ion mobility show great potential for applications as cathodes or solid electrolytes. Through periodic DFT calculations, a Bronsted-Evans-Polanyi-type scaling relation for migration barriers of different charge carriers in ASc(2)S(4) and ASc(2)Se(4) spinel compounds was identified. Combining this scaling relation with a descriptor based on easily accessible observables provides a conceptual framework to investigate ion mobility in d(0)-metal-based spinel chalcogenides with reduced computational effort. This approach was validated for various d(0)-metal-based spinel chalcogenide compounds and led to the identification of d(0)-metal-based CaB2O4 spinels as promising compounds for high Ca ion mobility.
BATTERIES & SUPERCAPS
(2022)
Article
Chemistry, Physical
Axel Gross
Summary: This study demonstrates that chemical reactions in heterogeneous catalysis can occur in a non-equilibrium fashion when the excess kinetic energy upon entering the potential well of a reaction intermediate is large enough, based on ab initio molecular dynamics simulations of the interaction of molecular oxygen with stepped Pt surfaces.
APPLIED SURFACE SCIENCE ADVANCES
(2022)
Article
Electrochemistry
Katharina Helmbrecht, Holger Euchner, Axel Gross
Summary: This study investigates the impact of dispersion forces on MO6S8 chevrel phase intercalation compounds. Dispersion forces have only a slight effect on the lattice spacing of the chevrel phase, but have a significant impact on the insertion voltage and charge carrier mobility. Additionally, the diffusion barriers of charge carriers in the chevrel phase scale linearly with ion size, regardless of the ion charge.
BATTERIES & SUPERCAPS
(2022)
Article
Chemistry, Multidisciplinary
Mohsen Sotoudeh, Axel Gross
Summary: By performing electronic structure calculations, we have identified a descriptor for ion mobility, which is composed of ionic radii, oxidation states, and Pauling electronegativities. The migration barriers in specific material classes are connected to this descriptor through linear scaling relations. This discovery has the potential to accelerate the search for materials with desired ion mobility properties.
