Date of Graduation

Spring 2016

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Kartik Ghosh

Keywords

zinc oxide, hydrothermal, solar energy, nano-bio interaction, crystal structure, electronic structure

Subject Categories

Materials Science and Engineering

Abstract

A molecule assisted hydrothermal synthesis of zinc oxide nanomaterials with L-lysine has been performed to understand the interaction between the biomolecule and the zinc oxide structures during synthesis. The molecule alters the growth kinetics during the formation of the nanomaterials in the hydrothermal reaction. This alters the size and shape of the materials as seen in the scanning electron microscope. X-ray diffraction results confirm the hexagonal Wurtzite structure that zinc oxide forms and indicates no other phases in the nanomaterial. The lattice parameters are not altered, but the atomic percentage of zinc to oxygen within the structure changes as analyzed by Topas crystallography software. Energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy both confirm a larger concentration of oxygen atoms on the surface. No other atoms are detected, indicating little contamination in the samples and no lysine is present after cleaning the samples. Raman spectroscopy indicates the enhancement of the A1(TO) mode in samples prepared with lysine. Ultraviolet-visible spectroscopy indicates a decreased energy band gap and increased concentration of defect energy level states significantly enhancing its optical absorption characteristics. Photoluminescence spectroscopy displays a slight red shift in the defect energy state peak for zinc oxide. These results indicate the possibility of using lysine as a treatment to enhance zinc oxides ability to be used as a solar absorbing medium in solar energy applications.

Copyright

© Austin Major Shearin

Open Access

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