Chemistry Commons^™

In-Situ/Operando57Fe Mössbauer Spectroscopic Technique And Its Applications In Nife-Based Electrocatalysts For Oxygen Evolution Reaction, Jafar Hussain Shah, Qi-Xian Xie, Zhi-Chong Kuang, Ri-Le Ge, Wen-Hui Zhou, Duo-Rong Liu, Alexandre I. Rykov, Xu-Ning Li, Jing-Shan Luo, Jun-Hu Wang

Journal of Electrochemistry

The development of highly efficient and cost-effective electrocatalysts for the sluggish oxygen evolution reaction (OER) remains a significant barrier to establish effective utilization of renewable energy storage systems and water splitting to produce clean fuel. The current status of the research in developing OER catalysts shows that NiFe-based oxygen evolution catalysts (OECs) have been proven as excellent and remarkable candidates for this purpose. But it is critically important to understand the factors that influence their activity and underlying mechanism for the development of state-of-the-art OER catalysts. Therefore, the development of in-situ/operando characterizations is urgently required to detect key …

In Situ Characterization Of Electrode Structure And Catalytic Processes In The Electrocatalytic Oxygen Reduction Reaction, Ya-Chen Feng, Xiang Wang, Yu-Qi Wang, Hui-Juan Yan, Dong Wang

Journal of Electrochemistry

As an electrochemical energy conversion system, fuel cell has the advantages of high energy conversion efficiency and high cleanliness. Oxygen reduction reaction (ORR), as an important cathode reaction in fuel cells, has received extensive attention. At present, the electrocatalysts are still one of the key materials restricting the further commercialization of fuel cells. The fundamental understanding on the catalytic mechanism of ORR is conducive to the development of electrocatalysts with the enhanced activity and high selectivity. This review aims to summarize the in situ characterization techniques used to study ORR. From this perspective, we first briefly introduce the advantages of …

Recent Advances In Electrical Transport Spectroscopy For The In Situ Measurement Of Electrochemical Interfaces, Zhang-Yan Mu, Meng-Ning Ding

Journal of Electrochemistry

Electrochemical/electrocatalytic technology has played a central role in achieving highly efficient energy conversion and storage. To date, the in-depth electrochemical research begins to require accurate and multi-dimensional information of electrochemical interfaces, which usually relies on the application of in situ characterizations. Electrical transport spectroscopy (ETS) is a newly developed measurement strategy based on chip-platform, and provides in situ information of electrochemical interfaces from a novel perspective due to a signal origin that is fundamentally different from typical spectroscopic and electrochemical techniques. In this tutorial review, the working principle and experimental setup of ETS are described in detail with the demonstration …

Rational Design Of Electrochemical Molecular Probes For Highly Selective And Long-Term Measurement In Vivo, Yue Wang, Li-Min Zhang, Yang Tian

Journal of Electrochemistry

Designing electrochemical interfaces for in vivo analysis of neurochemicals with high selectivity and long-term stability is vital for monitoring dynamic variation and dissecting the complex mechanisms of pathogenesis in living animals. This review focuses on the development of electrochemical interfaces based on rational design of molecular probes for in vivo measurement with high selectivity and high stability from three aspects: (1) Specific recognition probes were rationally designed and created to remarkably improve the selectivity of in vivo analysis in a complicated brain environment. (2) The Au-C≡C functionalized surface was developed to remarkably enhance the stability of molecular assembly, and employed …

Selective Co2 Reduction To Formate On Heterostructured Sn/Sno2 Nanoparticles Promoted By Carbon Layer Networks, Xue Teng, Yanli Niu, Shuaiqi Gong, Xuan Liu, Zuofeng Chen

Journal of Electrochemistry

Tin (Sn)-based materials have emerged as promising electrocatalysts for selective reduction of CO₂ to formate, but their overall performances are still limited by electrode structures which govern the accessibility to active sites, the electron transfer kinetics, and the catalytic stability. In this study, the heterostructured Sn/SnO₂ nanoparticles dispersed by N-doped carbon layer networks (Sn/SnO₂@NC) were synthesized by a melt-recrystallization method taking the low melting point of Sn (m.p. 232oC). The N-doped carbon layer networks derived from polydopamine could attract more electrons on the electrocatalyst, serve as conductive agents and protect the ultrafine nanoparticles from agglomeration and …

Efficient Capture Of Co2 And Its Selective Reduction To Formic Acid Using Tin-Based Nanomaterials, Emmanuel Oluwaseun Abdul

Dissertations and Theses

CO₂ emissions from the combustion of fossil fuels and other anthropogenic sources have become the main contributing factors to global warming. Chemical methods of absorbing/capturing CO₂ from combustion flue gases have made it a sought-after approach in engineering emission solutions because of its simplistic and convenient operation and high absorption efficiency. The conversion of CO₂ into renewable fuels and high energy density chemicals by clean and economic processes has drawn scientists' attention over the decades. The electrocatalytic conversion of CO₂ using Sn-based materials has been demonstrated to be a promising method for producing formate, an important …

Synthesis And Advanced Characterization Of Energy Materials, Erik Sarnello

Graduate Research Theses & Dissertations

Catalysts are used in an extremely broad range of systems including everything from biological systems to industrial processes. An ideal catalyst offers robust stability and high activity. This work focuses on the synthesis and characterization of materials that show promise in the field of catalysis. Advanced synchrotron characterization techniques and unique experimental design are highlighted to provide foundation work that will provide the necessary information to aid in designing and fabricating catalytic materials. Supported metal nanoparticle (SMN) catalysts are enormously crucial for many catalytic applications. However, catalyst deactivation, caused by sintering and coke formation, is a ubiquitous problem that significantly …

Electrochemical Gelation Of Metal Chalcogenide Quantum Dots, Chathuranga Chinthana Hewa Rahinduwage

Wayne State University Dissertations

Quantum dots (QDs) are attractive because of their unique size-dependent optical and electronic properties and high surface area. They are tested in research for diverse applications, including energy conversion, catalysis, and sensing. Assembling QDs into functional solid-state devices while preserving their attractive properties is a challenge. Methods currently under the research are not effective in directly fabricating QDs onto devices, making large area assemblies, maintaining the high surface area by forming 3D porous structures, and conducting electricity for applications such as sensing. QD gels are an example of QD assemblies that consist of a 3D porous interconnected QD network. They …

Biomedical Applications Of Lanthanide Nanomaterials, For Imaging, Sensing And Therapy, Qize Zhang, Stephen O'Brien, Jan Grimm

Publications and Research

The application of nanomaterials made of rare earth elements within biomedical sciences continues to make significant progress. The rare earth elements, also called the lanthanides, play an essential role in modern life through materials and electronics. As we learn more about their utility, function, and underlying physics, we can contemplate extending their applications to biomedicine. This particularly applies to diagnosis and radiation therapy due to their relatively unique features, such as an ultra-wide Stokes shift in the luminescence, variable magnetism and potentially tunable properties, due to the library of lanthanides available and their multivalent oxidation state chemistry. The ability to …

Characterization Of Nanoparticles Using Inductively-Coupled Plasma Mass Spectrometry, Jabez D. Campbell

MSU Graduate Theses

Nanomaterials are a relatively new class of materials that have many applications which span a wide host of fields from medical products to consumer products. The possible compositions and forms of nanomaterials are just as varied as the applications. Therefore, a versatile characterization method is needed for researchers and regulators alike to ensure nanomaterials are properly used. Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS) is a functional method that could fill the characterization need in the nanomaterial research field. Using data from both SP-ICP-MS tests and data from literature established characterization methods, the viability of making SP-ICP-MS the standard …

Copper Nanoparticles In-Situ Anchored On Nitrogen-Doped Carbon For High-Efficiency Oxygen Reduction Reaction Electrocatalyst, Hui-Fang Yuan, Yue Zhang, Xing-Wu Zhai, Li-Bing Hu, Gui-Xian Ge, Gang Wang, Feng Yu, Bin Dai

Journal of Electrochemistry

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m 2·g-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm3·g-1. The most positive Gibbs free …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Effect Of Aluminum Alloy Surface Modification On Adhesion Of The Modified Polyurethane Coating And Its Corrosion Protective Performance, Xian-Yin Kuang, Shao-Qiang Jin, Yan-Hui Cao, Yan-Mei Zhang, Shi-Gang Dong, Long-Hui Zhu, Li-Wen Lin, Chang-Jian Lin

Journal of Electrochemistry

The ordinary organic coatings on aluminum alloy usually encounter a problem of low adhesion to the substrate, which results in destruction and failure of the long-term protective performance of the anticorrosion systems. The surface modification of aluminum alloy is able to enhance the adhesion of organic coating on aluminum alloys, and to improve their protective performance. In this work, a combined surface modification of anodic oxidation and mussel adhesion protein/CeO₂/3-aminopropyltriethoxysilane composite film (MCA) was developed on the aluminum alloy. The adhesion of modified polyurethane coated on the treated aluminum alloy and its corrosion protective performance were evaluated comprehensively …

Synthesis Of Polyethylene Glycol-Based Hydrogels And Silver/Gold Nanostructures For Biomedical Applications, Isabelle Ishimwe Niyonshuti

Graduate Theses and Dissertations

This work focuses on the synthesis of biocompatible polyethylene glycol (PEG)-based hydrogels, silver nanoparticles (AgNPs), and silver-gold nanocages (Ag-AuNCs) for biomedical applications. The dissertation includes two parts with Part I on the work of PEG-based hydrogel for wound healing applications and Part II on the work of Ag/Au nanostructures for antimicrobial applications. Part I studies PEG-based hydrogel for the delivery of fibroblast growth factors (FGFs) for wound healing applications, aiming to overcome the challenge of designing hydrogels capable of the sustained release of bioactive FGFs. This research develops new biocompatible anionic injectable hydrogel formulations based on Poly (Oligo Ethylene Glycol …

Multifunctional Programmable Self-Assembled Nanoparticles In Nanomedicine, Yoshie Sakamaki

Graduate Theses and Dissertations

Developing methodologies to control the architecture of nanoparticles (NPs) at the atomic level prevents their inhomogeneity and leads to a variety of expected functions. Rationally designed nanoparticles can either be programmed or crystallized structures into pre-determined structures achieving tunable particle pore size and physiochemistry. In this dissertation, two broad classes of multifunctional nanoparticles are developed, metal-organic frameworks and DNA-NP aggregates.

Metal-organic frameworks are a novel class of highly porous crystalline materials built from organic linkers and metal cluster-based secondary building units. However, applications in bioremediation have not been developed very well especially in applications regarding drug delivery systems (DDS). The …

The Profound Photophysical Effects Of Organic Chromophore Connectivity And Coupling, David J. Walwark Jr

Nanoscience and Microsystems ETDs

Through-bond and through-space interactions between chromophores are shown to have wide-ranging effects on photophysical outcomes upon light absorption in organic molecules. In collapsed poly(3-hexylthiophene), through-space coupling creates hybrid chromophores that act as energy sinks for nearby excitons and favorable sites for molecular oxygen to dock. Upon excitation with visible light the highly-coupled chromophores react with the docked oxygen and subsequently do not quench nearby excitons as efficiently. In tetramer arrays of perylene diimide chromophores the central moiety through-bond connectivity is synthesized in two variants which exhibit vastly different single-molecule blinking behavior and theoretically-predicted electronic transition character. In the more-connected tetramer …

Aptamer-Based Voltammetric Biosensing For The Detection Of Codeine And Fentanyl In Sweat And Saliva, Rosa Lashantez Cromartie

FIU Electronic Theses and Dissertations

Despite the many governmental and medicinal restrictions created to combat the opioid epidemic in the United States, opioid abuse and overdose rates continue to rise. The development of an aptamer-based voltammetric sensor and biosensor is described in this dissertation. The aim was to develop a low-cost, sensitive, and specific aptamer-based sensor for on-site, label-free determination of codeine and fentanyl in biological fluids. To do this, the surfaces of screen-printed carbon electrodes (SPCE) were modified with gold nanoparticles (AuNPs), followed by the addition of single-stranded DNA aptamers. These were covalently bound to the electrode surface. Operations of the sensors were collected …

The Primarily Undergraduate Nanomaterials Cooperative: A New Model For Supporting Collaborative Research At Small Institutions On A National Scale, Steven M. Huges, Mark P. Hendricks, Katherine M. Mullaugh, Mary E. Anderson, Anne K. Bently, Justin G. Clar, Clyde A. Daly Jr., Mark D. Ellison, Z. Vivian Feng, Natalia I. Gonzalex-Pech, Leslie S. Hamachi, Christine L. Heinecke, Joseph D. Keene, Adam M. Maley, Andrea M. Munro, Peter N. Njoki, Jacob H. Olshansky, Katherine E. Plass, Kathryn R. Riley, Matthew D. Sonntag, Sarah K. St. Angelo, Lucas B. Thompson, Emily J. Tollefson, Lauren E. Toote, Korin E. Wheeler

Chemistry Faculty Publications

The Primarily Undergraduate Nanomaterials Cooperative (PUNC) is an organization for research-active faculty studying nanomaterials at Primarily Undergraduate Institutions (PUIs), where undergraduate teaching and research go hand-in-hand. In this perspective, we outline the differences in maintaining an active research group at a PUI compared to an R1 institution. We also discuss the work of PUNC, which focuses on community building, instrument sharing, and facilitating new collaborations. Currently consisting of 37 members from across the United States, PUNC has created an online community consisting of its Web site (nanocooperative.org), a weekly online summer group meeting program for faculty and students, …

Fundamentals Of Electrochemical Impedance Spectroscopy For Macrohomogeneous Porous Electrodes, Xiang Li, Qiu-An Huang, Wei-Heng Li, Yu-Xuan Bai, Jia Wang, Yang Liu, Yu-Feng Zhao, Juan Wang, Jiu-Jun Zhang

Journal of Electrochemistry

Electrochemical impedance spectroscopy (EIS) can be used to diagnose charge transfer reactions and mass transport in porous electrodes. The charge transfer reactions include interfacial charge accumulation and charge conduction as well as electrochemical reaction. In this paper, the complex phasor method is developed under the macrohomogeneous assumption to build an impedance model of porous electrodes for clarifying several vague expressions in the traditional approaches. The following researches are carried out: (1) Identifying characteristic parameters for the porous electrodes, including electrode electronic conductivity σ₁, electrolyte ionic conductivity σ₂, interface charge transfer conductivity g_ct, unit area …

Mathematical Expression And Quantitative Analysis Of Impedance Spectrum On The Interface Of Glassy Carbon Electrode, Lei Cheng, Pu-Xuan Yan, You-Jun Fan, Hua-Hong Zou, Hong Liang

Journal of Electrochemistry

Glassy carbon electrode (GCE) is a common basic electrode for various electrochemical sensors, and the detection properties are determined by its interfacial characteristics. In this paper, we established an equivalent circuit including electrolyte resistance (R_el), charge transport resistance (R_ct), diffusion impedance (R_di, C_di), electrochemical (oxidation/reduction) reaction impedance (R_R, C_R), surface adsorption impedance (R_ads , C_ads), double-layer capacitance (C_DL), and derived the mathematical expression for the equivalent circuit. The R_el and C_DL are contributed by inactive …

Molecular Dynamics Simulations Of Self-Assemblies In Nature And Nanotechnology, Phu Khanh Tang

Dissertations, Theses, and Capstone Projects

Nature usually divides complex systems into smaller building blocks specializing in a few tasks since one entity cannot achieve everything. Therefore, self-assembly is a robust tool exploited by Nature to build hierarchical systems that accomplish unique functions. The cell membrane distinguishes itself as an example of Nature’s self-assembly, defining and protecting the cell. By mimicking Nature’s designs using synthetically designed self-assemblies, researchers with advanced nanotechnological comprehension can manipulate these synthetic self-assemblies to improve many aspects of modern medicine and materials science. Understanding the competing underlying molecular interactions in self-assembly is always of interest to the academic scientific community and industry. …

Preparation And Electrochemical Evaluation Of Mos2/Graphene Quantum Dots As A Catalyst For Hydrogen Evolution In Microbial Electrolysis Cell, Hong-Yan Dai, Hui-Min Yang, Xian Liu, Xiu-Li Song, Zhen-Hai Liang

Journal of Electrochemistry

Microbial electrolysis cell (MEC) is a relatively new bioelectrochemical technology that produces H₂ and meanwhile treats organic wastewater. Cathode hydrogen evolution catalyst plays a key role in MEC. The doping of Graphene Quantum Dots (GQDs) into MoS₂ nanosheets can improve the catalytic activity of MoS₂ by creating abundant defect sites both in the edge plane and the basal plane, as well as enhancing the electrical conductivity. In this paper, using Na₂MoO₄ , cysteine and GQDs as raw materials, a series of MoS₂/GQDs composites were firstly synthesized via hydrothermal method, and then loaded …

Storage Performance And Mechanism Of Mose2 Nanospheres In Lithium And Magnesium Ion Batteries, Yi Peng, Wei Zhang, Fang-Zhen Zuo, Hao-Ying Lv, Kai-Jun Hong

Journal of Electrochemistry

Molybdenum diselenide (MoSe₂) is a two-dimensional (2D) transition metal dichalcogenide (TMD) material, attracting wide attention in lithium ion battery (LIB) and exhibiting great potential in next-generation magnesium ion battery (MIB) due to its unique layered structure with fast ion mobility and weak van der Waals interlayer interaction. However, the reported literatures related to MoSe₂ mainly focus on the enhancement of performance in LIB without deep storage mechanisms investigations. Meanwhile,the magnesium storage capacity and mechanisms have not been explored. In this work, MoSe₂ nanospheres were synthesized via wet chemical route and followed by annealing treatment. When used …

Design And Development Of 2d Functional Semiconductor Nanocrystals, Andrew Hunter Davis

Dissertations - ALL

Anisotropic nanocrystals (NCs) have become of keen interest in recent years, especially for applications in optoelectronic devices due to their directionally oriented emissions, narrow emission spectra, and suitable morphologies for device integration. Of the desired anisotropic NCs, two-dimensional (2D) NCs are of profound interest, due to their impressive optical and electronic properties as well as their prospective advantages towards applications in layered optoelectronic devices, such as solar cells. However, 2D NCs face many challenges, including limited synthetic derivation, as well as decreased stability and optical response, due to their large surface-to-volume ratio and reactive planar surface increasing surface defect state …

Thermoelectric Transport In Disordered Organic And Inorganic Semiconductors, Meenakshi Upadhyaya

Doctoral Dissertations

The need for alternative energy sources has led to extensive research on optimizing the conversion efficiency of thermoelectric (TE) materials. TE efficiency is governed by figure-of-merit (ZT) and it has been an enormously challenging task to increase ZT > 1 despite decades of research due to the interdependence of material properties. Most doped inorganic semiconductors have a high electrical conductivity and moderate Seebeck coefficient, but ZT is still limited by their high lattice thermal conductivity. One approach to address this problem is to decrease thermal conductivity by means of alloying and nanostructuring, another is to consider materials with an inherently low …

Molecular Dynamics Simulations Of Ion Transport Through Electrically Stressed Biological Membranes, Federica Castellani

Biomedical Engineering Theses & Dissertations

The cell membrane is a selectively permeable barrier that controls the transport of ions, molecules, and other materials into and out of a cell. The manipulation of the cell membrane permeability is the basis for several biotechnological and biomedical applications, including electroporation. Electroporation (or electropermeabilization) occurs when the application of an external electric pulse causes water intrusion into the membrane interior and the formation of conductive transmembrane electropores. These electropores allow drugs, genetic material, and other normally impermeant molecules to enter a cell. Despite years of study, the complex mechanisms underlying this process are still not well understood. Molecular dynamics …

Synthesis And Electrochemical Study Of Cuau Nanodendrites For Co2 Reduction, Siltamaki Dylan, Chen Shuai, Rahmati Farnood, Lipkowski Jacek, Chen Ai-Cheng

Journal of Electrochemistry

The conversion of carbon dioxide (CO₂) to carbon monoxide (CO) and other value-added products is an interesting approach for carbon-containing fuel synthesis using renewable and clean energy. The electrochemical reduction of CO₂ is one of the promising strategies for the storage of intermittent renewable energy resources. The development of electrocatalysts with high activity and stability is vital in the electrochemical CO₂ reduction process. In this study, copper and gold alloyed (CuAu) electrodes with nanodendritic structures were synthesized using a facile electrodeposition method. The CuAu nanodendrites with the atomic ratio of Cu to Au being approximately 1:1 …

Studies And Progresses On Hole Metallization In High-Density Interconnected Printed Circuit Boards, Zhao-Yun Wang, Lei Jin, Jia-Qiang Yang, Wei-Qing Li, Dong-Ping Zhan, Fang-Zu Yang, Shi-Gang Sun

Journal of Electrochemistry

Printed circuit boards (PCBs) are almost the core components of all electronic systems. With the rapid development of sciences and technologies, PCBs are gradually developing in the direction of multi-layer, thin and high-density wiring due to the functionalization, miniaturization, lightweight and high reliability of electronic products, as well as the widespread popularization of the subminiature package such as chip scale package (CSP) and ball grid array (BGA). Therefore, High-density interconnected printed circuit boards (HDI-PCBs) arise. Hole metallization is one of the core technologies in HDI-PCBs and includes two processes composed of conductive treatment and electron electroplating. Electroless copper plating, as …

Mathematical Model For Measuring The Concentration Of Nanoparticles In A Liquid During Sedimentation, Safaa Mohammed Ridha Hussien Hussien, Airat Sakhabutdinov, Vladimir Anfinogentov, Maxim Danilaev, Vladimir Kuklin, Oleg Morozov

Karbala International Journal of Modern Science

Expanding the application areas of polymer composite materials with dispersed filler requires the development of technologies providing the required mechanical characteristics. One of these methods is based on forming a thin polymer shell on the surfaces of particles. At the same time, it is impossible to take into account the mechanical characteristics of a thin polymer shell due to its ultra-small thickness. The mechanical properties of the polymer shell can be determined only by indirect methods, and prior information can improve the adequacy of the properties determination. The method, which allows reducing the requirements for composite sample preparation, is proposed. …

Investigations Into Size And Surface Control Of Silicon Nanocrystals For Improved Optical Properties, James Donald Barnes

Dissertations and Theses

The discovery of visible photoluminescence (PL) from nanocrystalline porous silicon in 1990 led to extensive research into the mechanisms of the emergent properties, and optimization of these properties, for use in applications. The widespread use of silicon nanoparticles (Si NPs) in commercial applications is currently limited by three main factors: 1) poor radiative recombination efficiency of the interband transition, 2) instability of the interband photoluminescence, and 3) a lack of scalable methods for producing Si NPs that are both highly crystalline and size monodisperse.

To address these limitations, this dissertation correlates changes in the photoluminescence properties of hydrogen passivated silicon …