Physical Chemistry Commons^™

Air-Stable Palladium N-Heterocyclic Carbene Based Ccc-Nhc Pincer Complexes: Synthesis, Characterization, Photophysical And Raman Vibrational Studies, And Dft Studies, Plus Observation Of An Abnormal Carbene Pincer, Jason A. Denny, Georgette M. Lang, Shane Autry, Vivek Dixit, Tyler L. Woodby, Annie Mcclellan, Jaclyn M. Trate, Nathan I. Hammer, Charles Edwin Webster, Thedford K. Hollis

CAS Publications

A series of CCC-NHC pincer Pd(II)X complexes, where X = Cl, Br, or I, were synthesized by a metalation/transmetalation reaction sequence and characterized by NMR and Raman spectroscopy, photophysical studies, X-ray crystallography, and DFT computational studies. This is the first detailed report of the CCC-NHC pincer Pd complexes analogous the previously reported Pt analogs. Photophysical measurements show that by varying the X ligand, the emission wavelength can be tuned. The chloride complex is a water and air stable blue emitter with a quantum yield of 46% and all three complexes have photostabilities >90%. A combined DFT and TD-DFT study has …

Effect Of Electronegativity On Environmentally Persistent Free Radical (Epfr) Formation, Persistence, And Toxicity On Transition Metal Oxides, Syed Monjur Ahmed

LSU Doctoral Dissertations

Environmentally persistent free radicals (EPFRs) are a group of emerging environmental pollutants. Owing to their resonance structures, EPFRs have significantly higher lifetimes than typical free radicals, and can induce the formation of reactive oxygen species (ROS) known to cause pulmonary and cardiovascular dysfunction. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface and exhibit enough stability to cause negative health and environmental effects. While aromatic and substituted aromatic precursors form EPFRs on TMO surface at elevated temperatures and numerous substituted organics are ubiquitous in various industrial processes and household products, studies have largely overlooked …

Substrate Interference And Strain In The Second-Harmonic Generation From Mose2 Monolayers, Sudeep Puri, Sneha Patel, Jose Luis Cabellos, Luis Enrique Rosas-Hernandez, Kaitlin Reynolds, Hugh O.H. Churchill, Salvador Barraza-Lopez, Bernardo S. Mendoza, Hiroyuki Nakamura

Physics Faculty Publications and Presentations

Nonlinear optical materials of atomic thickness, such as non-centrosymmetric 2H transition metal dichalcogenide monolayers, have a second-order nonlinear susceptibility (χ⁽²⁾) whose intensity can be tuned by strain. However, whether χ⁽²⁾ is enhanced or reduced by tensile strain is a subject of conflicting reports. Here, we grow high-quality MoSe₂ monolayers under controlled biaxial strain created by two different substrates and study their linear and nonlinear optical responses with a combination of experimental and theoretical approaches. Up to a 15-fold overall enhancement in second-harmonic generation (SHG) intensity is observed from MoSe₂ monolayers grown on SiO₂ when …

Selective Hydrolysis Of Heterooligosaccharides By Poly(Acrylate) Gel Catalysts, Susanna Striegler

Chemistry & Biochemistry Faculty Publications and Presentations

Natural glycoside hydrolases are distinguished by their ability to hydrolyze glycosidic bonds with high efficiency and selectivity. This feature is achieved through specific interactions in the active site during catalytic turnover and is not just facilitated by two catalytically active amino acids. Intrigued by these features, a biomimetic α-galactosidase mimic was developed using an empirical catalyst design. Starting with a library of 704 gels of which 250 have a unique composition synthesized from TEGDMA cross-linker and 7 selected monomers, 238 monomodal gels are evaluated for their ability to hydrolyze the 1→6 α-glycosidic bond in the disaccharide melibiose. Among those, 13 …

Electronic Communication Between Co And Ru Sites Decorated On Nitrogen-Doped Carbon Nanotubes Boost The Alkaline Hydrogen Evolution Reaction, Meng-Ting Gao, Ying Wei, Xue-Meng Hu, Wenj-Jie Zhu, Qing-Qing Liu, Jin-Yuan Qiang, Wan-Wan Liu, Ying Wang, Xu Li, Jian-Feng Huang, Yong-Qiang Feng

Journal of Electrochemistry

Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction (HER) remains a significant challenge. Here, a novel and efficient cobalt (Co), ruthenium (Ru) bimetallic electrocatalyst composed of CoRu nanoalloy decorated on the N-doped carbon nanotubes (CoRu@N-CNTs), was prepared by reacting fullerenol with melamine via hydrothermal treatment and followed by pyrolysis. Benefiting from the electronic communication between Co and Ru sites, the as-obtained CoRu@N-CNTs catalyst exhibited superior electrocatalytic HER activity. To deliver a current density of 10 mA·cm^–2, it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV·dec …

Zhong-Qun Tian, Academician And Honorary Member Of Electrochemistry Committee Chinese Chemical Society, Achieved "Raman Lifetime Award", Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Optimization Of Channel Structure Of Alkaline Water Electrolyzer By Using An Expanded Mesh As A Bipolar Plate, Hai-Yan Xiong, Zhen-Xiao Zhu, Xin Gao, Chen-Ming Fan, Hui-Bao Luan, Bing Li

Journal of Electrochemistry

Alkaline water electrolysis (AWE) is the most mature technology for hydrogen production by water electrolysis. Alkaline water electrolyzer consists of multiple electrolysis cells, and a single cell consists of a diaphragm, electrodes, bipolar plates and end plates, etc. The existing industrial bipolar plate channel is concave-convex structure, which is manufactured by complicated and high-cost mold punching. This structure still results in uneven electrolyte flow and low current density in the electrolytic cell, further increasing in energy consumption and cost of AWE. Thereby, in this article, the electrochemical and flow model is firstly constructed, based on the existing industrial concave and …

Chinese Chemical Society: First Young Scholars' Symposium On Electrosynthesis Held Successfully, Chinese Society Of Electrochemistry (Cse)

Journal of Electrochemistry

No abstract provided.

2024 Tianmulake Advanced Anode Materials Innovation Forum And Sixth National Conference Of Advanced Battery Failure Analysis And Testing Technology Concluded Successfully, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Aging Characteristics Of Lithium-Ion Battery Under Fast Charging Based On Electrochemical-Thermal-Mechanical Coupling Model, Dong-Xu Zuo, Pei-Chao Li

Journal of Electrochemistry

The aging characteristics of lithium-ion battery (LIB) under fast charging is investigated based on an electrochemical-thermal-mechanical (ETM) coupling model. Firstly, the ETM coupling model is established by COMSOL Multiphysics. Subsequently, a long cycle test was conducted to explore the aging characteristics of LIB. Specifically, the effects of charging (C) rate and cycle number on battery aging are analyzed in terms of nonuniform distribution of solid electrolyte interface (SEI), SEI formation, thermal stability and stress characteristics. The results indicate that the increases in C rate and cycling led to an increase in the degree of nonuniform distribution of SEI, and thus …

Destiny Functional Theory (Dft) Study Of Water Autoionization In Solvated Clusters, Kurt Kolasinski, Alex M. Salkowski

Chemistry Faculty Publications

We have implemented a cluster-continuum method using density functional theory (DFT) to model water clusters and various charged species derived from water. Two aims of this study are to determine the minimal basis required for proper modeling of water autoionization and the minimum number of explicit water molecules that are required to properly model the energetics of solvation. The thermodynamics of water autoionization converge following a modified power law to deliver chemically accurate values of the Gibbs energy change for autoionization with tractably small clusters. Convergence is slower and not exponential as assumed in previous work. We identify the n …

Incorporating Solvation Thermodynamic Mapping In Computer-Aided Drug Design, Yeonji Ji

Dissertations, Theses, and Capstone Projects

Advancements in computational techniques have revolutionized structure-based drug design, substantially improving the efficiency and effectiveness of the drug discovery process by reducing time, costs, and labor requirements. These advancements include various methods, such as investigating small molecule ligands binding to proteins, exploring alternative protein conformations, and solvation mapping on the protein surfaces. Among these methods, understanding the correlation between protein-ligand binding and the role of solvation is important.

A fundamental concept in protein-ligand binding is shape and electrostatic complementarity, which is complicated by the inherent flexibility of proteins. In the absence of small molecule ligands, proteins are complementary to surface …

Deciphering The Interdomain Coupling In A Gram-Negative Bacterial Membrane Insertase, Adithya Polasa, Shadi A. Badiee, Mahmoud Moradi

Chemistry & Biochemistry Faculty Publications and Presentations

YidC is a membrane protein that plays an important role in inserting newly generated proteins into lipid membranes. The Sec-dependent complex is responsible for inserting proteins into the lipid bilayer in bacteria. YidC facilitates the insertion and folding of membrane proteins, both in conjunction with the Sec complex and independently. Additionally, YidC acts as a chaperone during the folding of proteins. Multiple investigations have conclusively shown that Gram-positive bacterial YidC has Sec-independent insertion mechanisms. Through the use of microsecond-level all-atom molecular dynamics (MD) simulations, we have carried out an in-depth investigation of the YidC protein originating from Gram-negative bacteria. This …

Asphalt-Binder Mixtures Evaluated By T1 Nmr Relaxometry, Rebecca M. Herndon, Jay Balasubramanian, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt pavements make up a majority of the essential transportation systems in the US. Asphalt mixtures age and degrade over time, reducing the pavement performance. Pavement performance critically depends on the aging of asphalt binder. The aging of asphalt binder during construction is traditionally modeled by rolling thin film oven (RTFO) testing, while aging during service life is modeled by pressure aging vessel (PAV) testing. Comparing these models to the aging of binders in actual pavements is limited because, to be used for current testing, binders must be separated from the pavement's aggregate by solvent extraction. Solvent extraction will, at …

Asphalt-Binder Mixtures Evaluated By T1 Nmr Relaxometry, Rebecca M. Herndon, Jay Balasubramanian, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt pavements make up a majority of the essential transportation systems in the US. Asphalt mixtures age and degrade over time, reducing the pavement performance. Pavement performance critically depends on the aging of asphalt binder. the aging of asphalt binder during construction is traditionally modeled by rolling thin film oven (RTFO) testing, while aging during service life is modeled by pressure aging vessel (PAV) testing. Comparing these models to the aging of binders in actual pavements is limited because, to be used for current testing, binders must be separated from the pavement's aggregate by solvent extraction. Solvent extraction will, at …

Nuclear Magnetic Resonance (Nmr) Assessment Of Bio And Crude Oil-Based Rejuvenation, Rebecca M. Herndon, Jay Balasubramanian, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binders in pavements lose their stability through aging and eventually fail in the field. Using nuclear magnetic resonance (NMR) to monitor the primary longitudinal relaxation time of asphalt samples and the ratio of material that carries this primary relaxation time has been shown to indicate the impact of ultraviolet (UV) radiation on the aging of asphalt pavements. Longitudinal NMR relaxation was used to investigate two types of proposed asphalt rejuvenators, a bio-oil-based rejuvenator and a crude-oil-based rejuvenator. Two different binders with the performance grades (PG) 64-22 and 76-22 were considered for their interactions with the rejuvenators. After 72 h …

Recent Advances On Ruthenium-Based Electrocatalysts For Lithium-Oxygen Batteries, Yu-Zhe Wang, Zhuo-Liang Jiang, Bo Wen, Yao-Hui Huang, Fu-Jun Li

Journal of Electrochemistry

Rechargeable lithium-oxygen (Li-O₂) batteries have attracted wide attention due to their high energy density. However, the sluggish cathode kinetics results in high overvoltage and poor cycling performance. Ruthenium (Ru)-based electrocatalysts have been demonstrated to be promising cathode catalysts to promote oxygen evolution reaction (OER). It facilitates decomposition of lithium peroxide (Li₂O₂) by adjusting Li₂O₂ morphologies, which is due to the strong interaction between Ru-based catalyst and superoxide anion (O₂^–) intermediate. In this review, the design strategies of Ru-based electrocatalysts are introduced to enhance their OER catalytic kinetics in …

Numerical Analysis Of Explosion Characteristics Of Vent Gas From 18650 Lifepo4 Batteries With Different States Of Charge, Shi-Lin Wang, Xu Gong, Li-Na Liu, Yi-Tong Li, Chen-Yu Zhang, Le-Jun Xu, Xu-Ning Feng, Huai-Bin Wang

Journal of Electrochemistry

The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries. Investigating the combustion and explosion hazards of lithium-ion batteries vent gas can provide guidance for rescue and protection in explosion accidents in energy storage stations and new energy vehicles, thereby promoting the application and development of lithium-ion batteries. Based on this understanding and combined with previous research on gas production from lithium-ion batteries, this article conducted a study on the combustion and explosion risks of vent gas from thermal runaway of 18650 LFP batteries with different states of …

2024 "Electrochemical Research Paradigms" Summer School Successfully Held, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Rate Law For Photoelectrochemical Water Splitting Over Cuo, Bo-Yuan Gao, Wen-Hua Leng

Journal of Electrochemistry

Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of hydrogen. However, the determination of rate law is rarely reported. To this purpose, copper oxide (CuO) is selected as a model photocathode in this study, and the photogenerated surface charge density, interfacial charge transfer rate constant and their relation to the water reduction rate (in terms of photocurrent) were investigated by a combination of (photo)electrochemical techniques. The results showed that the charge transfer rate constant is exponential-dependent on the surface charge density, and that the photocurrent equals to the product of the charge transfer rate constant …