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Full-Text Articles in Nanoscience and Nanotechnology

Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari Apr 2016

Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari

Electronic Thesis and Dissertation Repository

This thesis explores the synthesis of metal oxide 1-D nanowires using a sol-gel method in supercritical carbon dioxide (sc-CO2), as an environmental friendly enabling solvent. Porous nanowires were synthesized and their performance was tested in dye sensitized solar cell and sacrifical hydrogen production. Titanium isopropoxide (TIP) was used as a precursor for titania synthesis while copper, bismuth and indium were examined as dopants, respectively. The sol-gel reactions were catalyzed by acetic acid in CO2 at a temperature of 60 °C and pressure of 5000 psi. It was observed that acetic acid/monomer ratio > 4 produced nanowires while a ...


Alloy Solute Interactions At Grain Boundaries And Nanoscale Interfaces In Copper, Luke Prestowitz May 2015

Alloy Solute Interactions At Grain Boundaries And Nanoscale Interfaces In Copper, Luke Prestowitz

Nanoscale Science & Engineering (discontinued with class year 2014)

To study grain boundary solute interactions we have developed recipes for co-electrodeposition of dilute copper alloys including Cu(Ni) and Cu(Co). Secondary Ion Mass Spectrometry (SIMS) was used to analyze the incorporation of solute into the copper film. In addition to the co-electrodeposition process we also used a drive-in diffusion model for Au, Ag, Co, and Ni. Atomic imaging in a scanning transmission electron microscope (STEM) was used to visualize and investigate solute at grain boundaries and interfaces in polygranular copper films. By understanding these interactions and pathways of alloying solutes in copper microstructures, we can more accurately predict ...


Nucleation And Growth Of Metals On Carbon Surfaces, David Victor Appy Jan 2014

Nucleation And Growth Of Metals On Carbon Surfaces, David Victor Appy

Graduate Theses and Dissertations

This thesis work presents an investigation of the basic interaction between metals and the carbon surfaces HOPG and amorphous carbon. This work was motivated by the discovery of a family of metal nanowires which grow as single crystals protruding substantially perpendicular to a substrate, where the substrate is held at elevated temperature (800-1100 K). The most prolific growth is seen for Cu on amorphous carbon substrates. The fabrication and properties of these wires have been pioneered by our collaborator, Dr. Gunther Richter, at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. They have potential uses in nanoscale mechanical ...


Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor Aug 2013

Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor

Theses and Dissertations

Platinum and Pt alloys are among the most important heterogeneous catalysts for many organic reactions and electrochemical reactions associated with the fuel cell technologies. How to reduce Pt usage while maintaining the performance of the catalysts becomes a subject for intensive research in materials chemistry. For heterogeneous catalysis, the catalytic reactivity and selectivity are strongly correlated with different crystallographic facets exposed on the surface. The facets with high-index planes whose Miller indices with at one is larger than unity are generally more active than those with low-index planes (e.g., {100}, {111}, and {110}). Tuning the morphology of the nanoparticles ...


Morphological Control Of Copper And Cuprous Oxide Nanoparticles Via Synthesis And Oxidation/Reduction Reactions, Ryan William Mowbray Jan 2013

Morphological Control Of Copper And Cuprous Oxide Nanoparticles Via Synthesis And Oxidation/Reduction Reactions, Ryan William Mowbray

Chemical & Biological Engineering Graduate Theses & Dissertations

Morphological structure at the nanoscale dictates material properties due to size and shape dependent effects which are not present in bulk materials. In this work, novel synthetic routes are presented for the synthesis of copper nanoparticles including cubes, octahedra and platelets which could find applications in catalysis and sensing applications. In addition, intermediate morphology of copper/cuprous oxide nanoparticles during reduction by hydrogen gas are characterized by UV-Vis spectroscopy and TEM imaging. The results of the UV-Vis characterization show that nanoparticle oxide reduction occurs by a different mechanism than reduction in the bulk due to short diffusion lengths and high ...