Doctoral Dissertations

Abstract

"Layered nanostructures of copper metal and cuprous oxide are electrodeposited from alkaline solutions of Cu(II) lactate at room temperature. The electrode potential oscillates spontaneously during constant-current deposition. The potential oscillations are attributed to the formation and breakdown of a rectifying Cu₂O/solution interface. A thin layer of pure Cu₂O is grown during the negative-going direction in the potential oscillations and a Cu/Cu₂O composite is formed at the positive-going direction in the potential oscillations. The thicknesses of the Cu₂O layers are in the nanometer range. The phase composition of the Cu/Cu₂O films is a function of the solution pH and applied current density for the galvanostatic deposition. The coper content increases as the applied current density is increased at a given pH and decreases as the pH of the solution is increased at a given applied current density. The copper content in the Cu/Cu₂O films increases as the applied potential is more negative at a given solution pH for the potentiostatic deposition. Linear sweep voltammetry was used to study the rectifying behavior of the Cu₂O/solution junction. The Schottky-like rectifying barrier decreases as the pH of the solution is increased with a relation of -0.046 eV/pH. The barrier height of the junction is 0.61 eV for a pH 9 solution and 0.49 eV for a pH 12 solution. The optical and electrical properties of pure cuprous oxide films were also studied. The electrodeposited Cu₂O film has a direct bandgap of 2.04 eV ± 0.06eV The Cu₂O films grown at pH = 9 show a strong [100] orientation, while Cu₂O films grown at pH = 12 show [111] orientation. The Cu₂O films grown at higher pH and more positive applied potential are more conductive"--Abstract, page iii.

Advisor(s)

Switzer, Jay A., 1950-

Committee Member(s)

Manuel, O. (Oliver), 1936
James, William Joseph
Collier, Harvest L.
O'Keefe, T. J. (Thomas J.)

Department(s)

Chemistry

Degree Name

Ph. D. in Chemistry

Sponsor(s)

National Science Foundation (U.S.)
United States. Office of Naval Research
University of Missouri Research Board

Comments

Electronic access to the full-text of this document is restricted to Missouri S&T users. Print thesis not available at Missouri S&T Library.

Print thesis lost & withdrawn; scan made from microfilm is best quality available.

Publisher

University of Missouri--Rolla

Publication Date

Summer 1998

Pagination

xix, 195 pages

Note about bibliography

Includes bibliographical references (pages 183-193)

Rights

© 1998 Ling-Yuang Huang, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Subject Headings

Electrochemical analysisCuprous oxideCopper compoundsNanostructured materialsElectrochemistry -- Materials

Thesis Number

T 7518

Print OCLC #

41415755

Electronic OCLC #

904020130

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