Engineering Commons^™

Gamma-Ray Radiation Effects In Graphene-Based Transistors With H-Bn Nanometer Film Substrates, E. J. Cazalas, Michael R. Hogsed, S. R. Vangala, Michael R. Snure, John W. Mcclory

Faculty Publications

Radiation effects on graphene field effect transistors (GFETs) with hexagonal boron nitride (h-BN) thin film substrates are investigated using 60Co gamma-ray radiation. This study examines the radiation response using many samples with varying h-BN film thicknesses (1.6 and 20 nm thickness) and graphene channel lengths (5 and 10 μm). These samples were exposed to a total ionizing dose of approximately 1 Mrad(Si). I-V measurements were taken at fixed time intervals between irradiations and postirradiation. Dirac point voltage and current are extracted from the I-V measurements, as well as mobility, Dirac voltage hysteresis, and the total number of GFETs that remain …

Microwave-Assisted Synthesis Of Graphene Supported Hexagonal Magnetite For Applications In Catalysis, Hany A. Elazab, M. A. Radwan, M. A. Sadek

Chemical Engineering

Herein, we report a rapid one-step synthetic method using microwave irradiation for growing magnetite nanocrystals on reduced graphene oxide sheets. This developed strategy allows decorating graphene sheets with magnetite nanocrystals of well-defined morphology as cubes using microwave-driven reduction of iron chloride using hydrazine hydrate as a reducing agent. The size and shape control was achieved via fine-tuning of the reaction conditions. The obtained results demonstrate the applicability of this microwave synthetic approach to control the morphology of the magnetite nanocrystals anchored on graphene sheets. Moreover, graphene sheets will enhance the nucleation and growth of magnetite nanoplates anchored on graphene. This …

Pd Nanoparticles Supported On Copper Oxide Prepared Via Microwave – Assisted Synthesis: An Efficient Catalyst For Suzuki Cross-Coupling, Hany A. Elazab Dr

Chemical Engineering

We report here a scientific investigation of a simple and versatile synthetic rote for the synthesis of palladium nanoparticles decorated with copper oxideand supported on reduced Graphene oxide (rGO) as a highly active catalyst usedfor Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (7000) and turnover frequency of 85000 h^-1. Pd-CuO nanoparticles supported on reduced Graphene oxide nanosheets (Pd-CuO/rGO) exhibited an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction …

Facile Synthesis Of Reduced Graphene Oxide-Supported Pd/Cuo Nano-Particles As An Efficient Catalyst For Cross-Coupling Reactions, Hany A. Elazab Dr

Chemical Engineering

The present communication reports a scientific investigation of a simple and versatile synthetic route for the synthesis of palladium nanoparticles decorated with copper oxide and supported on reduced graphene oxide (rGO). They are used as a highly active catalyst of Suzuki, Heck, and Sonogashira cross coupling reactions with a remarkable turnover number of 7000 and a turnover frequency of 85000 h-1. The Pd-CuO nanoparticles supported on reduced graphene oxide nanosheets (Pd-CuO/rGO) exhibit an outstanding performance through a high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method is used to prepare this efficient catalyst using microwave irradiation …

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti₃C₂T_x and Ti₂CT_x) with a SiO₂ coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account …

Evaluating The Scalability Of The Sonication Method Of Graphene Oxide Synthesis, Evan Dexter

Honors Program Projects

Graphene is a new material that was first isolated in 2004, and consists of one to a few atomic layers of carbon in a lattice sheet structure. Graphene has high tensile strength, high surface area, very low electrical resistance, and various other special properties that make it an excellent material for use in emerging technologies in the categories of electrical components, energy systems, and high strength applications. The production scale of graphene sheets and its variations is currently limited to laboratory use, with increasing research being conducted toward the development of manufacturing techniques of the material. We conducted experiments to …

Hydrothermal Synthesis Of Graphene Supported Pd/Fe3o4 Nanoparticles As Efficient Magnetic Catalysts For Suzuki Cross – Coupling, Hany A. Elazab Dr

Chemical Engineering

This research reports a reproducible, reliable, and efficient method for preparing palladium nanoparticles dispersed on a composite of Fe3O4 and graphene as an active catalyst with high efficiency for being used in Suzuki cross – coupling reactions. Graphene supported Pd/Fe3O4 nanoparticles (Pd/Fe3O4/G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst recyclability was up to nine times without losing its high catalytic activity. The catalyst was prepared using hydrothermal synthesis; the prepared catalyst is magnetic in order to facilitate catalyst separation out of the reaction medium after reaction completion simply through using a strong magnet. This …

Study Of Charge Carrier Transport In Graphene And Graphite As Two Dimensional And Quasi-Two Dimensional Materials And Their Interfaces, Nalat Sornkhampan

FIU Electronic Theses and Dissertations

Evidence of superconductivity in phosphorous-doped graphite and graphene has been observed at temperatures in the vicinity of 260 K. This evidence includes transport current, magnetic susceptibility, Hall and Nernst measurements. All of these measurements indicate a transition of a type II superconductor without a phase of type I until below the limits of the measurement capabilities.

Vortex states are inferred from periodically repeated steps in the R vs. T characteristics of Highly Oriented Pyrolytic Graphite and exfoliated doped multilayer graphene. The presence of vortices has been confirmed with thermal gradient driven Nernst measurements. Magnetic susceptibility measurements have shown results qualitatively …

Thermal Transport In Layer-By-Layer Assembled Polycrystalline Graphene Films, David Estrada, Alondra Perez

Materials Science and Engineering Faculty Publications and Presentations

New technologies are emerging which allow us to manipulate and assemble 2-dimensional (2D) building blocks, such as graphene, into synthetic van der Waals (vdW) solids. Assembly of such vdW solids has enabled novel electronic devices and could lead to control over anisotropic thermal properties through tuning of inter-layer coupling and phonon scattering. Here we report the systematic control of heat flow in graphene-based vdW solids assembled in a layer-by-layer (LBL) fashion. In-plane thermal measurements (between 100 K and 400 K) reveal substrate and grain boundary scattering limit thermal transport in vdW solids composed of one to four transferred layers of …

Graphene Based Functional Devices: A Short Review, Rong Wang, Xin Gang Ren, Ze Yan, Li (Lijun) Jun Jiang, Wei E.I. Sha, Guang Cun Shan

Electrical and Computer Engineering Faculty Research & Creative Works

Graphene is an ideal 2D material system bridging electronic and photonic devices. It also breaks the fundamental speed and size limits by electronics and photonics, respectively. Graphene offers multiple functions of signal transmission, emission, modulation, and detection in a broad band, high speed, compact size, and low loss. Here, we have a brief view of graphene based functional devices at microwave, terahertz, and optical frequencies. Their fundamental physics and computational models were discussed as well.

Open-Source Automated Chemical Vapor Deposition System For The Production Of Two-Dimensional Nanomaterials, Lizandra Williams-Godwin, Dale Brown, Richard Livingston, Tyler Webb, Lynn Karriem, Elton Graugnard, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

The study of two- dimensional (2D) materials is a rapidly growing area within nanomaterials research. However, the high equipment costs, which include the processing systems necessary for creating these materials, can be a barrier to entry for some researchers interested in studying these novel materials. Such process systems include those used for chemical vapor deposition, a preferred method for making these materials. To address this challenge, this article presents the first open-source design for an automated chemical vapor deposition system that can be built for less than a third of the cost for a comparable commercial system. The materials and …

Coupling Topological Insulator Snsb2te4 Nanodots With Highly Doped Graphene For High-Rate Energy Storage, Zhibin Wu, Gemeng Liang, Wei Kong Pang, Tengfei Zhou, Zhenxiang Cheng, Wenchao Zhang, Ye Liu, Bernt Johannessen, Zaiping Guo

Australian Institute for Innovative Materials - Papers

Topological insulators have spurred worldwide interest, but their advantageous properties have scarcely been explored in terms of electrochemical energy storage, and their high-rate capability and long-term cycling stability still remain a significant challenge to harvest. p-Type topological insulator SnSb2Te4 nanodots anchoring on few-layered graphene (SnSb2Te4/G) are synthesized as a stable anode for high-rate lithium-ion batteries and potassium-ion batteries through a ball-milling method. These SnSb2Te4/G composite electrodes show ultralong cycle lifespan (478 mAh g−1 at 1 A g−1 after 1000 cycles) and excellent rate capability (remaining 373 mAh g−1 even at 10 A g−1) in Li-ion storage owing to the rapid …

Facile Synthesis Of Reduced Graphene Oxide-Supported Pd/Cuo Nanoparticles As An Efficient Catalyst For Cross-Coupling Reactions, Hany A. Elazab, M. A. Sadek, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present communication reports a scientific investigation of a simple and versatile synthetic route for the synthesis of palladium nanoparticles decorated with copper oxide and supported on reduced graphene oxide (rGO). They are used as a highly active catalyst of Suzuki, Heck, and Sonogashira cross coupling reactions with a remarkable turnover number of 7000 and a turnover frequency of 85000 h-1. The Pd-CuO nanoparticles supported on reduced graphene oxide nanosheets (Pd-CuO/rGO) exhibit an outstanding performance through a high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method is used to prepare this efficient catalyst using microwave irradiation …

Hydrothermal Synthesis Of Graphene Supported Pd/Fe 3 O 4 Nanoparticles As Efficient Magnetic Catalysts For Suzuki Cross – Coupling, Hany A. Elazab, Mamdouh A. Gadalla, Mohamed A. Sadek, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

This research reports a reproducible, reliable, and efficient method for preparing palladium nanoparticles dispersed on a composite of Fe₃O₄ and graphene as an active catalyst with high efficiency for being used in Suzuki cross – coupling reactions. Graphene supported Pd/Fe₃O₄ nanoparticles (Pd/Fe₃O₄ /G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst recyclability was up to nine times without losing its high catalytic activity. The catalyst was prepared using hydrothermal synthesis; the prepared catalyst is magnetic in order to facilitate catalyst separation out of the reaction medium …

Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles As An Efficient Nanocomposite For Catalysis Applications In Cross-Coupling Reactions, Hany A. Elazab, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h-1. Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction …