Excited State Interactions in Graphene Oxide-Semiconductor/Metal Nanoparticle Architectures for Sensing and Energy Conversion

Doctoral Dissertation

Abstract

The recent emergence of graphene, along with its unique and impressive set of properties, has resulted in a concerted effort to incorporate the material into electronic devices and composite materials. Graphene oxide, a chemically modified form of graphene which can be produced economically and in large scale, is one of the most common starting materials for making graphene composite materials with improved conductivity, photovoltaic performance, and photocatalytic activity, to name a few examples. This dissertation describes progress made in understanding and quantifying the electronic properties of graphene oxide as they relate to electron storage and shuttling in composite materials.

A more complete understanding of the nature of electronic interactions in graphene composites was achieved through two processes: 1) A dual electron-titration showing storage and shuttling of electrons in reduced graphene oxide. 2) A method developed to isolate the energy and electron transfer pathways involved in the deactivation of excited CdSe quantum dots by RGO. The results obtained from these two processes provide insight into the electronic interactions between graphene, semiconductors, and metals.

Additionally, composite films were constructed to demonstrate the electron transfer properties of reduced graphene oxide. TiO2-reduced graphene oxide films were made via a simple drop-cast technique. The films show enhanced photovoltaic and photocatalytic characteristics when compared to TiO2-only films. A stacked architecture incorporating single-layer reduced graphene oxide on thin TiO2 nanoparticle films was developed as a method for illumination-controlled deposition of metal nanoparticles. Films of metal nanoparticles made using this technique were employed as Surface Enhanced Resonance Raman (SERRS) sensors and show nano-molar sensitivity. Finally, quantum dot-reduced graphene oxide composites were made via an electrophoretic deposition process. The resulting films were used as photoanodes in photoelectrochemical cells and show improvements in photocurrent generation of up to ~150% over CdSe-only photoanodes.

On account of the advantageous electronic properties and improved device performance, the work described in this dissertation provides a basis for further exploration in the field of reduced graphene composite materials. The versatility of the material along with the methods designed for customizable film construction makes it an ideal material for next-generation sensors and catalyst materials.

Attributes

Attribute NameValues
URN
  • etd-04202012-105214

Author Ian V. Lightcap
Advisor Dr. Prashant Kamat
Contributor Dr. Franklin Tao, Committee Member
Contributor Dr. Prashant Kamat, Committee Chair
Contributor Dr. Marya Lieberman, Committee Member
Contributor Dr. Ken Kuno, Committee Member
Degree Level Doctoral Dissertation
Degree Discipline Chemistry and Biochemistry
Degree Name PhD
Defense Date
  • 2012-04-12

Submission Date 2012-04-20
Country
  • United States of America

Subject
  • semiconductor

  • solar cell

  • catalysis

  • SERRS

  • electron transfer

  • graphene oxide

  • energy transfer

  • nanotechnology

  • sensing

  • energy conversion

  • metal

  • SERS

  • surface enhanced raman

  • sensor

  • graphene

  • reduced graphene oxide

  • nanoparticle

  • photovoltaic

Publisher
  • University of Notre Dame

Language
  • English

Record Visibility and Access Public
Content License
  • All rights reserved

Departments and Units

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