Micropatterning And Functionalization Of Single Layer Graphene: Tuning Its Electron Transport Properties,
2024
Department of Chemistry, College of Chemistry and Chemical Engineering; State Key Laboratory of Physical Chemistry of Solid Surfaces (PCOSS); Engineering Research Center of Electrochemical Technologies of Ministry of Education; Xiamen University; Xiamen 361005, China
Micropatterning And Functionalization Of Single Layer Graphene: Tuning Its Electron Transport Properties, Miao-Miao Cui, Lian-Huan Han, Lan-Ping Zeng, Jia-Yao Guo, Wei-Ying Song, Chuan Liu, Yuan-Fei Wu, Shi-Yi Luo, Yun-Hua Liu, Dong-Ping Zhan
Journal of Electrochemistry
As a promising 2D material, graphene exhibits excellent physical properties including single-atom-scale thickness and remarkably high charge carrier mobility. However, its semi-metallic nature with a zero bandgap poses challenges for its application in high-performance field-effect transistors (FETs). In order to overcome these limitations, various approaches have been explored to modulate graphene's bandgap, including nanoscale confinement, external field induction, doping, and chemical micropatterning. Nevertheless, the stability and controllability still need to be improved. In this study, we propose a feasible method that combines electrochemical bromination and photolithography to precisely tune the electron transport properties of single layer graphene (SLG). Through this …
Size Limits And Fission Channels Of Doubly Charged Noble Gas Clusters,
2024
University of Innsbruck
Size Limits And Fission Channels Of Doubly Charged Noble Gas Clusters, Ianessa Stromberg, Stefan Bergmeister, Lisa Ganner, Fabio Zappa, Paul Scheier, Olof Echt, Elisabeth Gruber
Faculty Publications
Small, highly charged liquid droplets are unstable with respect to spontaneous charge separation when their size drops below the Rayleigh limit or, in other words, their fissility parameter X exceeds the value 1. The absence of small doubly charged atomic cluster ions in mass spectra below an element-specific appearance size na has sometimes been attributed to the onset of barrierless fission at X = 1. However, more realistic models suggest that na marks the size below which the rate of fission surpasses that of competing dissociative channels, and the Rayleigh limit of doubly charged van der Waals clusters …
Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes,
2024
The University of Texas Rio Grande Valley
Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin
Research Symposium
Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations to elucidate Pt(0)-mediated C–CP bond activation mechanisms in phosphaalkynes. Investigating the …
Doubly Charged Dimers And Trimers Of Heavy Noble Gases,
2024
University of Innsbruck
Doubly Charged Dimers And Trimers Of Heavy Noble Gases, Gabriel Schöpfer, Stefan Bergmeister, Milan Ončák, Ianessa Stromberg, Masoomeh Mahmoodi-Darian, Paul Scheier, Olof Echt, Elisabeth Gruber
Faculty Publications
Many doubly charged heteronuclear dimers are metastable or even thermodynamically stable with respect to charge separation. Homonuclear dicationic dimers, however, are more difficult to form. He22+ was the first noble gas dimer predicted to be metastable and, decades later, observed. Ne22+ is the only other dicationic noble gas dimer that has been detected so far. Here, we present a novel approach to form fragile dicationic species, by post-ionization of singly charged ions that are embedded in helium nanodroplets (HNDs). Bare ions are then extracted by colliding the HNDs with helium gas. We detect homonuclear doubly charged …
The Infrared Absorption Spectrum Of Phenylacetylene And Its Deuterated Isotopologue In The Mid- To Far-Ir,
2024
Chapman University
The Infrared Absorption Spectrum Of Phenylacetylene And Its Deuterated Isotopologue In The Mid- To Far-Ir, Vincent J. Esposito, Pierro Ferrari, Wybren Jan Buma, Ryan C. Fortenberry, Christiaan Boersma, Alessandra Candian, Alexander G. G. M. Tielens
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Anharmonicity strongly influences the absorption and emission spectra of polycyclic aromatic hydrocarbon (PAH) molecules. Here, IR–UV ion-dip spectroscopy experiments together with detailed anharmonic computations reveal the presence of fundamental, overtone, as well as 2- and 3-quanta combination band transitions in the far- and mid-infrared absorption spectra of phenylacetylene and its singly deuterated isotopologue. Strong absorption features in the 400–900 cm−1 range originate from CH(D) in-plane and out-of-plane wags and bends, as well as bending motions including the C≡C and CH bonds of the acetylene substituent and the aromatic ring. For phenylacetylene, every absorption feature is assigned either directly or …
Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno,
2024
Louisiana State University at Baton Rouge
Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben Oumnov, Orhan Kizilkaya, Randall W. Hall, Philip T. Sprunger, Robert L. Cook
Natural Sciences and Mathematics | Faculty Scholarship
Environmentally persistent free radicals (EPFRs), a group of emerging pollutants, have significantly longer lifetimes than typical free radicals. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface involving electron charge transfer between the organic and TMO. In this paper, dihalogenated benzenes were incorporated to study the role of electronegativity in the electron transfer process to obtain a fundamental knowledge of EPFR formation mechanism on ZnO. Upon chemisorption on ZnO nanoparticles at 250 °C, electron paramagnetic resonance (EPR) confirms the formation of oxygen adjacent carbon-centered organic free radicals with concentrations between 1016 and 1017 spins/g. …
Water Potential From Adaptive Force Matching For Ice And Liquid With Revised Dispersion Predicts Supercooled Liquid Anomalies In Good Agreement With Two Independent Experimental Fits,
2024
University of Arkansas, Fayetteville
Water Potential From Adaptive Force Matching For Ice And Liquid With Revised Dispersion Predicts Supercooled Liquid Anomalies In Good Agreement With Two Independent Experimental Fits, Raymond Weldon, Feng Wang
Chemistry & Biochemistry Faculty Publications and Presentations
A revised version of the Water potential from Adaptive force matching for Ice and Liquid (WAIL) was developed by using the previous data set for fitting the WAIL model but with a dispersion term calculated using symmetry adapted perturbation theory (SAPT). The model has no adjustable parameters and relies solely on fitting first-principles information. The new model, named revised WAIL (rWAIL), shows improved predictions of most properties of water when compared to the previously published WAIL model. The rWAIL model also compares favorably to other first-principles-derived water models, such as MB-Pol, at only a fraction of the computational cost. The …
Joint Time-Frequency Analysis: Taking Charge Penetration Depth And Current Spatial Distribution In The Single Pore As An Example,
2024
Institute for Sustainable Energy/College of Science, Shanghai University, Shanghai 201800, China
Joint Time-Frequency Analysis: Taking Charge Penetration Depth And Current Spatial Distribution In The Single Pore As An Example, Nan Wang, Qiu-An Huang, Wei-Heng Li, Yu-Xuan Bai, Jiu-Jun Zhang
Journal of Electrochemistry
In recent years, joint time-frequency analysis has once again become a research hotspot. Supercapacitors have high power density and long service life, however, in order to balance between power density and energy density, two key factors need to be considered: (i) the specific surface area of the porous matrix; (ii) the electrolyte accessibility to the intra-pore space of porous carbon matrix. Electrochemical impedance spectra are extensively used to investigate charge penetration ratio and charge storage mechanism in the porous electrode for capacitance energy storage. Furthermore, similar results could be obtained by different methods such as stable-state analysis in the frequency …
Automated Workflow For Redox Potentials And Acidity Constants Calculations From Machine Learning Molecular Dynamics,
2024
a State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen 361005, Fujian, China
Automated Workflow For Redox Potentials And Acidity Constants Calculations From Machine Learning Molecular Dynamics, Feng Wang, Jun Cheng
Journal of Electrochemistry
Redox potentials and acidity constants are key properties for evaluating the performance of energy materials. To achieve computational design of new generation of energy materials with higher performances, computing redox potentials and acidity constants with computational chemistry have attracted lots of attention. However, many works are done by using implicit solvation models, which is difficult to be applied to complex solvation environments due to hard parameterization. Recently, ab initio molecular dynamics (AIMD) has been applied to investigate real electrolytes with complex solvation. Furthermore, AIMD based free energy calculation methods have been established to calculate these physical chemical properties accurately. However, …
Confirmation Of Anomalous-Heat Report,
2024
New Energy Times 369-B 3rd St. #556, San Rafael, CA, 94901
Confirmation Of Anomalous-Heat Report, Steven B. Krivit, Melvin H. Miles
Journal of Electrochemistry
This study identifies, for the first time, critical calculation errors made by Nathan Lewis and his co-authors, in their study presented on May 1, 1989, at the American Physical Society meeting in Baltimore, Maryland. Lewis et al. analysed calorimetrically measured heat results in nine experiments reported by Martin Fleischmann and his co-authors. According to the Lewis et al. analysis, each of the experiments, where calculated for no recombination, showed anomalous power losses. When we used the same raw data, our corrected calculations indicate that each experiment showed anomalous power gains. As such, these data suggest the possibility of a new, …
Measurements Of Rate Constant For Electrode Reactions,
2024
Department of Mechanical and Electrical Engineering, Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, Fujian, China
Measurements Of Rate Constant For Electrode Reactions, Lian-Huan Han, Jia-Yao Guo, Miao-Miao Cui
Journal of Electrochemistry
Standard electron-transfer rate constant is one of the intrinsic properties for an electrochemical reaction, which is significant in the study of electrode kinetics. It is a key criterion for one to clarify the mechanism and pathway of a specific electrochemical reaction, and to screening and design the electrocatalysts and battery materials. Herein, we will introduce the measuring methods of rate constant for electrode reactions, including polarization curve, rotating disk electrode, ultramicroelectrode, scanning electrochemical microscopy, electrochemical impedance spectroscopy, current step, potential step and cyclic voltammetry, etc., to provide a guide to investigate electrode kinetics for graduate students and researchers in the …
Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations,
2024
CUNY Graduate Center
Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations, Dhwanit Rahul Dave
Dissertations, Theses, and Capstone Projects
The challenge of establishing a sustainable and circular economy for materials in medicine and technology necessitates bioinspired design. Nature's intricate machinery, forged through evolution, relies on a finite set of biomolecular building blocks with through-bond and through-space interactions. Repurposing these molecular building blocks requires a seamless integration of computational modeling, design, and experimental validation. The tools and concepts developed in this thesis pioneer new directions in peptide-materials design, grounded in fundamental principles of physical chemistry. We present a synergistic approach that integrates experimental designs and computational methods, specifically molecular dynamics simulations, to gain in-depth molecular insights crucial for advancing the …
Thin-Film Nanocomposite Membranes With Alumina Nanoparticles For Textile Wastewater Treatment Applications,
2024
American University in Cairo
Thin-Film Nanocomposite Membranes With Alumina Nanoparticles For Textile Wastewater Treatment Applications, Amr Mohamed Tayel
Theses and Dissertations
Thin-film nanocomposite (TFN) membranes are gaining great interest in industrial wastewater treatment due to their superior performance, especially for higher water flux and pollutants’ rejection, as well as improved chemical, thermal and mechanical stabilities, compared to other types of membranes. The performance of TFN membranes can be enhanced using different types of nanofillers, among which ceramic nanomaterials, such as Al2O3, offer a promising potential for applications involving treatment of industrial wastewater such as textile effluents, and this is due to their stability, hydrophilicity, and relative low cost. The study of the TFN membrane properties and structure allows the optimization and …
On The Exact Helium Wave Function Expansion, Ii, An Exponential Modulated Form,
2024
University of Connecticut
On The Exact Helium Wave Function Expansion, Ii, An Exponential Modulated Form, Carl W. David
Chemistry Education Materials
A 11S wave function’s expansion for 2 electron atoms and ions is proposed employing an appropriate exponential factor and Fock’s logarithmic terms. The leading coefficient’s are presented.
Rational Design Of Heterostructured Nanomaterials For Accelerating Electrocatalytic Hydrogen Evolution Reaction Kinetics In Alkaline Media,
2024
Shanghai Key Laboratory for R&D and Application of Metallic Functional Materials, Institute of New Energy for Vehicles, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
Rational Design Of Heterostructured Nanomaterials For Accelerating Electrocatalytic Hydrogen Evolution Reaction Kinetics In Alkaline Media, Hai-Bin Ma, Xiao-Yan Zhou, Jia-Yi Li, Hong-Fei Cheng, Ji-Wei Ma
Journal of Electrochemistry
Owing to the merits of high energy density, as well as clean and sustainable properties, hydrogen has been deemed to be a prominent alternative energy to traditional fossil fuels. Electrocatalytic hydrogen evolution reaction (HER) has been considered to be mostly promising for achieving green hydrogen production, and has been widely studied in acidic and alkaline solutions. In particular, HER in alkaline media has high potential to achieve large-scale hydrogen production because of the increased durability of electrode materials. However, for the currently most prominent catalyst Pt, its HER kinetics in an alkaline solution is generally 2–3 orders lower than that …
Stability Of A Solid Oxide Cell Stack Under Direct Internal-Reforming Of Hydrogen-Blended Methane,
2024
Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang, China
Stability Of A Solid Oxide Cell Stack Under Direct Internal-Reforming Of Hydrogen-Blended Methane, Ya-Fei Tang, An-Qi Wu, Bei-Bei Han, Hua Liu, Shan-Jun Bao, Wang-Lin Lin, Ming Chen, Wan-Bing Guan, Subhash C. Singhal
Journal of Electrochemistry
In this work, the long-term stability and degradation mechanism of a direct internal-reforming solid oxide fuel cell stack (IR-SOFC stack) using hydrogen-blended methane steam reforming were investigated. An overall degradation rate of 2.3%·kh–1 was found after the stack was operated for 3000 hours, indicating a good long-term stability. However, the voltages of the two cells in the stack were increased at the rates of 3.38 mV·kh–1 and 3.78 mV·kh–1, while the area specific resistances of the three metal interconnects in the stack were increased to 0.276 Ω·cm2, 0.254 Ω·cm2 and 0.249 Ω·cm2 …
Monodispersed Cu-Tcpp/Cu2O Hybrid Microspheres: A Superior Cascade Electrocatalyst Toward Co2 Reduction To C2 Products,
2024
New Energy Research Institute, School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Guangzhou 510006, Guangdong, China
Monodispersed Cu-Tcpp/Cu2O Hybrid Microspheres: A Superior Cascade Electrocatalyst Toward Co2 Reduction To C2 Products, Zi-Xuan Wan, Aidar Kuchkaev, Dmitry Yakhvarov, Xiong-Wu Kang
Journal of Electrochemistry
The electrochemical conversion of carbon dioxide (CO2) into valuable chemicals is a feasible way to mitigate the negative impacts of overmuch CO2 emissions. Porphyrin-based metal organic frameworks (MOFs) are expected to be used for selective and efficient electrochemical CO2 reduction (ECR) with porous structure and ordered active sites. Herein, we report the synthesis of a monodispersed and spherical organic/inorganic hybrid Cu-TCPP@Cu2O electrocatalyst composed of Cu-TCPP (TCPP=tetrakis (4-carboxyphenyl) porphyrin) and Cu2O, where TCPP plays significant roles in regulating the morphology. In-situ formed Cu during ECR process in combination with Cu-TCPP (Cu-TCPP@Cu) can suppress …
Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum,
2024
University of Mississippi
Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum, Ryan C. Fortenberry, Vincent J. Esposito
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
With the recent radioastronomical detection of cis-trans-carbonic acid (H2CO3) in a molecular cloud toward the Galactic center, the more stable but currently unobserved cis-cis conformer is shown here to have strong IR features. While the higher-energy cis-trans-carbonic acid was detected at millimeter and centimeter wavelengths, owing to its larger dipole moment, the vibrational structure of cis-cis-carbonic acid is more amenable to its observation at micron wavelengths. Even so, both conformers have relatively large IR intensities, and some of these fall in regions not dominated by polycyclic aromatic hydrocarbons. Water features may inhibit observation …
Surface Modification Of Poly(4,4'-Oxydiphenilene Pyromellitimide) With Low-Pressure Plasma Treatment,
2024
University of South Florida
Surface Modification Of Poly(4,4'-Oxydiphenilene Pyromellitimide) With Low-Pressure Plasma Treatment, Cihan Aktas
USF Tampa Graduate Theses and Dissertations
This study explores the change of the wetting characteristics of commercially availablepolyimide (PI), Kapton® HN, films a type of poly(4,4′-oxydiphenylene-pyromellitimide), following treatment with low-pressure plasmas of carbon tetrafluoride (CF4), air, hydrogen (H2), carbon-dioxide (CO2) and oxygen (O2) gases as well as the surface texturing via laser-exposure procedure. The water contact angle (CA) and surface free energy (SFE) of untreated PI films were determined as 82.4°±0.8 and 45.0±0.3 mN/m, respectively. After CF4 plasma gas treatment, the CA value of PI films increased to 110.2°±1.0, while it decreased to 9.3°±2.3 after O2 plasma gas treatment. The surface free energy (SFE) of PI …
Predicting The Reactions Of Cs2, Ocs, And Co2 With Group Iv And Group Vi Transition Metal Oxides,
2024
Morehead State University
Predicting The Reactions Of Cs2, Ocs, And Co2 With Group Iv And Group Vi Transition Metal Oxides, Marissa Shea Blair, Zachary Ryan Lee Phd, David A. Dixon Phd
Posters-at-the-Capitol
Building on a recent serious of high level electronic structure studies of Lewis acid gas reactions with metal oxide sorbents, DFT (B3LYP and ωB97X-D) and CCSD(T) methods are being used to predict the Lewis acid-base addition (physisorption) and formation of metal oxide carbonate/thiocarbonate formation (chemisorption) reactions of CS2, OCS, and CO2 of CS2, OCS, and CO2 with Group IV (MO2)n and Group VI (MO3)n (n = 1 - 3) nanoclusters. For the Group IV oxides, chemisorption to form terminal carbonates and thiocarbonates is predicted to be the most favored, with thiocarbonate ligand binding energies slightly more exothermic than their carbonate …
