Materials Science and Engineering Commons^™

An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2C/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen

Journal of Electrochemistry

A 40% Pt on Mo₂C/GC catalyst has been prepared by ion exchange method. The mechanism of methanol electrooxidation on Pt-Mo₂C/GC and commercial Pt/C catalysts in acidic media was studied by cyclic voltammetry, XRD measurements and in-situ Fourier transform infrared spectroelectrochemistry. The results revealed that the Pt nanoparticles were uniformly dispersed on Mo₂C/GC with an average particle size of 3 nm. The cyclic voltammetric and chronopotentiometric experiments indicated that Pt-Mo₂C/GC catalyst exhibited a better performance for methanol oxidation than that of Pt/C in acid solution. A negative shift over 90 mV of the …

Effect Of Ti/Pbo2 Electrodes Doped With Different Elements On Electrocatalytic Oxidation Characteristics Of Phenol, Xiao-Lei Liu, Yuan-Yuan Dan, Hai-Yan Lu, Hai-Bo Lin, Ming-Li Ouyang, Chuan-Jun Yun

Journal of Electrochemistry

Three types of electrodes, namely, Ti/PbO₂, F-doped PbO₂ (Ti/PbO₂-F) and nano-Co₃O₄-doped PbO₂ (Ti/PbO₂+Nano-Co₃O₄) electrodes, were prepared by electro-deposition method on the Ti substrate with the interlayer of SnO₂-Sb₂O₅. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the compositions, structures and film morphologies of the electrodes. Electrocatalytic oxidation characteristics to phenol on the prepared electrodes were investigated by electrochemical method. The experimental results showed that compared with the Ti/PbO₂ electrode, the potentials of oxygen …

A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

Developing Pt-lean catalysts for oxygen reduction reaction (ORR) is the key for large-scale application of proton exchange membrane fuel cell (PEMFC). In this paper, we have proposed a multiple-descriptor strategy for screening efficient and durable ORR alloy catalysts of low Pt content. We argue that an ideal Pt-based bimetallic alloy catalyst for ORR should possess simultaneously negative alloy formation energy, negative surface segregation energy of Pt and a lower oxygen binding ability than pure Pt. By performing detailed DFT calculations on the thermodynamics, surface chemistry and electronic properties of various Pt-M alloys (M refers to non-precious transition metals in the …

Sodium Carbonate Catalyzed Photoelectrochemical Water Splitting Over Tio2 Nanotubes Photoanode, De-Sheng Kong, Jing Wang, Xue-Di Zhang, Xi Zhao, Chao Wang, Yuan-Yuan Feng, Wen-Juan Li

Journal of Electrochemistry

Surface recombination of the photogenerated electron-hole pairs at semiconductor/electrolyte interface is one of the most essential reasons responsible for lowering photoconversion efficiency (Φ) of light to chemical energy for photoelectrochemical (PEC) water splitting reaction. In this paper, the catalytic effect of sodium carbonate on the oxygen evolution reaction (OER) over TiO₂ nanotubes photoanode during PEC water splitting was investigated by performing photocurrent and ac impedance measurements. It was demonstrated that the addiction of 1 mmol•L^-1 Na₂CO₃ in 0.5 mol•L^-1 NaClO₄ electrolyte can effectively improve the charge transfer properties for the photogenerated holes across …

Applications Of Ellipsometry In The Investigations Of Electrode-Solution Interface, Jing-Lei Lei, Liang-Liu Wu, Ling-Jie Li, Sheng-Mao Wu, Sheng-Tao Zhang

Journal of Electrochemistry

Ellipsometry is an optical technique with high-sensitivity to quantitatively obtain surface/interface properties such as thickness andrefractive index by analyzing the changes in polarized light reflected from the surface/interface. Its noncontacting and nondestructivenature makes it possible to acquire thein situreal-time information of the change at the surface/interface. Therefore, ellipsometry has been used widely in the electrochemical investigations. In this paper, based on the brief introduction of the measurementprinciple of ellipsometry, the current progress and the future trends of ellipsometry in electrochemistry arediscussed. The applications of ellipsometry in the fields of conversion and storage of electrochemical energy, electrochemistry ofmaterials science,electroanalysisand bioelectrochemistry are …

Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye

Journal of Electrochemistry

O

xygen reduction reaction (ORR) on glycin (NH₂CH₂COOH) modified Pt(111) electrode has been investigated using hanging meniscus rotating disk electrode system (HMRD) in 0.05 mol•L^-1 H₂SO₄ and 0.1 mol•L^-1 HClO₄ solutions, respectively. Cyclic voltammograms of the glycin modified Pt (111) electrode measured in 0.05 mol•L^-1 H₂SO₄ solution similar to that of CN^- modified Pt(111) electrodes, demonstrating that sulfate adsorption is strongly inhibited at the glycin modified Pt(111). From the polarization curve of ORR recorded in 0.05 mol•L^-1 H₂SO₄ solution, it is …

Porous Electrodes With High Pt Utilization Obtained By Ion-Exchange/Electrodeposition, Si-Guo Chen, Wei Ding, Xue-Qiang Qi, Li Li, Zi-Hua Deng, Zi-Dong Wei

Journal of Electrochemistry

We report a novel method based on ion-exchange/electrodeposition (IEE) for constructing high Pt utilization porous electrodes. The electrode prepared using IEE was assessed by linear sweep voltammetry (LSV), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and single cell test. The preliminary results show that the undesired ion-exchange between Pt anion and surface functional group in carbon black can be eliminated through the electrode preparation process, and every Pt particle prepared by IEE is expected to be deposited on the three-phase reaction zone and thus can be fully utilized in fuel cell reactions. The Pt particle size, shape and distribution …

Material Characterization And The Effects Of Moisture And Drying On Injection Molded Torlon 5030, Michael R. Di Re

Master's Theses

The effects of water absorption and drying were studied on injection molded Torlon 5030, a high performance thermoplastic fabricated by Solvay Specialty Polymers. Torlon 5030 contains 30% by weight glass fibers in a polyamide-imide base resin. The objective behind this work was to test and better define relevant properties for industrial applications using this material. While the material design guide offers information on many mechanical properties including tensile, fatigue, and creep data; there is little to no publicly published data on the effects of water absorption and any subsequent drying of Torlon 5030. Blistering was also studied. With exposure to …

Compositional Tuning Of Structural Stability Of Lithiated Cubic Titania Via A Vacancy-Filling Mechanism Under High Pressure, Hui Xiong

Materials Science and Engineering Faculty Publications and Presentations

Experimental and theoretical studies on the compositional dependence of stability and compressibility in lithiated cubic titania are presented. The crystalline-to-amorphous phase transition pressure increases monotonically with Li concentration (from ∼17.5  GPa for delithiated to no phase transition for fully lithiated cubic titania up to 60 GPa). The associated enhancement in structural stability is postulated to arise from a vacancy filling mechanism in which an applied pressure drives interstitial Li ions to vacancy sites in the oxide interior. The results are of significance for understanding mechanisms of structural response of metal oxide electrode materials at high pressures as well as emerging …

High Strain Rate Superplasticity In Friction Stir Processed Ultrafine Grained Mg-Al-Zn Alloys, A. Mohan, W. Yuan, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stirs processing of a rolled AZ31 alloy, and a high pressure die cast AZ91 alloy produced ultrafine grained materials with average grain size of 0.8μm and 0.5μm, respectively. Tensile testing was done in the temperature range of 210-360°C and strain rate range of 1x10^-4-3x10^-2s^-1. Higher amounts of Β-precipitates in AZ91 thermally stabilized the microstructure up to 330°C. Friction processed ultrafine grain AZ91 exhibited high strain rate super plasticity at all tested temperatures. The best elongation of 1251% was achieved at a strain rate of 1x10^-2s^-1 and temperature of 330°C. The …

Guided Wave-Based J-Integral Estimation For Dynamic Stress Intensity Factors Using 3d Scanning Laser Doppler Vibrometry, J. Ayers, Christopher Todd Owen, Eric D. Swenson, Anindya Ghoshal, V. Weiss

Faculty Publications

The application of guided waves to interrogate remote areas of structural components has been researched extensively in characterizing damage. However, there exists a sparsity of work in using piezoelectric transducer-generated guided waves as a method of assessing stress intensity factors (SIF). This quantitative information enables accurate estimation of the remaining life of metallic structures exhibiting cracks, such as military and commercial transport vehicles. The proposed full wavefield approach, based on 3D laser vibrometry and piezoelectric transducer-generated guided waves, provides a practical means for estimation of dynamic stress intensity factors (DSIF) through local strain energy mapping via the J-integral. Strain energies …

Effect Of Friction Stir Processing On The Tensile And Fatigue Behavior Of A Cast A206 Alloy, R. Kapoor, K. Kandasamy, R. S. Mishra, J. A. Baumann, G. Grant

Materials Science and Engineering Faculty Research & Creative Works

The microstructure of cast Al alloy A206 was modified using friction stir processing (FSP) to eliminate porosity, break down intermetallic particles and refine the grains. The inference from differential scanning calorimetry is that the nugget region of the as-FSP material contained primarily GP zones. Uniaxial tensile tests and bending fatigue tests were carried out at room temperature on A206 alloy in the cast and T4 conditions and after FSP with different heat treatments - as-FSP, FSP and aging, and FSP with solutionizing and aging. These produced varied microstructures with combinations of pores, grain sizes, precipitate types and particle sizes. The …

Interfacial Bonding And Electronic Structure Of Hfo2/Gasb Interfaces: A First-Principles Study, Ka Xiong, Wei-Hua Wang, Dmitry Zhernokletov, Santosh Kc, Roberto Longo, R. Wallace, Kyeongjae Cho

Faculty Publications

The interfacial bonding and electronic structure of HfO2/GaSb interfaces has been investigated through first principles calculations. The calculated electronic structures of these interfaces reveal that some O-rich interfaces are semiconducting interfaces without any gap states. In contrast, for the interfaces with lower interfacial O content, gap states appear in the GaSb band gap, close to the conduction band. The valence band offsets are found to vary from 2.2 eV to 3.6 eV, depending on the interfacial O content. Our results suggest that GaSb is a suitable material to form high quality interface with HfO2.

Scaffold For Bone And Tissue Repair In Mammals, D. E. Day, Steven B. Jung

Materials Science and Engineering Faculty Research & Creative Works

A mammalian tissue scaffold and method for making a tissue scaffold including a rigid scaffold body of biocompatible glass fibers bonded together and in special alignment to define open channels within the scaffold to allow fluid flow into and within the scaffold.

Experimental Study Of Nanofiber Production Through Forcespinning, Simon Padron, Arturo Fuentes, Dumitru Caruntu, Karen Lozano

Mechanical Engineering Faculty Publications

A newly developed method of producing nanofibers, called forcespinning, has proven to be a viable alternative to mass produce nanofibers. Unlike electrospinning, the most common method currently being employed (which draws fibers through the use of electrostatic force), forcespinning utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers (given that electric fields are not required) while also providing a significant increase in yield and ease of production. This work presents a detailed explanation of the fiber formation process. The study is conducted using high speed photography to capture the jet initiation process at …

Surface Interactions On Glass Optics During Fabrication, Post Processing & Laser Operation, Tayyab Suratwala

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Glasses For Energy Storage: Advancing The Energy Density And Safety Of Batteries, Steve W. Martin

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Glass And Glass Ceramic For Nonlinear Optics: Fundamentals To Applications, T. Cardinal, E. Fargin, J. J, Videau, Y. Petit, G. Guery, M. Dussauze, F. Adamiertz, V. Rodriguez, L. Canioni, A.| Royon

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Surface Chemistry Of Glass: Interfacial Water And Mechanochemical Properties, Hongtu He, Laura C. Bradley, Zachary R. Dilworth, Carlo G. Pantano, Seong H. Kim

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Coated Glass For Energy Efficient Buildings: Spectral Selectivity, Angular Dependence & Time Variability, C. G. Granqvist

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Sealing Glasses For Electrochemical Devices, Richard K. Brow

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Fundamentals Of Indentation Cracking In Glass: A Measure Of Strength?, Satoshi Yoshida

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Sharp Contact Damage In Ion-Exchanged Cover Glass, Tim Gross, Jim Price, Scott Glaesemann

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Ion Transport Across Grain Boundaries In Fast Lithium Ion Conducting Glass Ceramics, Bernhard Roling, Katharina I. Gries, Michael Gellert, Kerstin Volz, Fabio Rosciano, Chihiro Yada

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Integrated Glass Substrates For Oled Lighting, Mehran Arbab

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Photovoltaic Industry & Role Of Glass For Reducing The Cost Of Solar Energy, Sener Oktik

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Alterations Of Glass Surfaces & Functional Coatings For Energy Conversion Systems, Joachim Deubener

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

A General Introduction For The Use And Needs Of Tcms, Driss Lamine

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Synthesis Of Graphene And Its Applications For Dye-Sensitized Solar Cells, Hui Wang

Dissertations, Master's Theses and Master's Reports - Open

Graphene, which is a two-dimensional carbon material, exhibits unique properties that promise its potential applications in photovoltaic devices. Dye-sensitized solar cell (DSSC) is a representative of the third generation photovoltaic devices. Therefore, it is important to synthesize graphene with special structures, which possess excellent properties for dye-sensitized solar cells.

This dissertation research was focused on (1) the effect of oxygen content on the structure of graphite oxide, (2) the stability of graphene oxide solution, (3) the application of graphene precipitate from graphene oxide solution as counter electrode for DSSCs, (4) the development of a novel synthesis method for the three-dimensional …

Extending Device Performance In Photonic Devices Using Piezoelectric Properties, Gregory Edward Triplett

Electrical and Computer Engineering Publications

This study focuses on the influence of epi-layer strain and piezoelectric effects in asymmetric GaInAs/GaAlAs action regions that potentially lead to intra-cavity frequency mixing. The theoretical limits for conduction and valence band offsets in lattice-matched semiconductor structures have resulted in the deployment of non-traditional approaches such as strain compensation to extend wavelength in intersubband devices, where strain limits are related to misfit dislocation generation. Strain and piezoelectric effects have been studied and verified using select photonic device designs. Metrics under this effort also included dipole strength, oscillator strength, and offset of energy transitions, which are strongly correlated with induced piezoelectric …