Electronic Theses and Dissertations

Date of Award

1-1-2022

Document Type

Dissertation

Degree Name

Ph.D. in Chemistry

Department

Chemistry and Biochemistry

First Advisor

Nathan I. Hammer

Second Advisor

Jared H. Delcamp

Third Advisor

Davita Watkins

Relational Format

dissertation/thesis

Abstract

A multitude of spectroscopic techniques were employed in the making of this dissertation to investigate materials with environmental, commercial, optoelectronic, bioimaging, and solar energy conversion applications. Graphene-like materials like biochar represent a field of study in which bioavailable materials are deployed for CO2 and heavy-metal adsorption to combat the detrimental effects of industry on the environment. Vibrational characterization of these materials via Raman spectroscopy is integral in elucidating the structure-function relationship and determining the best approach for material preparation and functionalization. Carbonaceous systems such as cellulose are also studied via Raman spectroscopy to interrogate the viability of cellulose nanocrystals as stabilizing agents in emulsions with a host of commercial and industrial applications. Emissive materials have near-limitless applications depending on the region in which they emit. Higher energy emission from metal-organic frameworks (MOFs) in the ultraviolet and visible regions is studied via steady-state and time-resolved photoluminescence. MOFs are frequently used in optoelectronic devices, and work herein provides insight into the three-dimensional framework of such materials. Lower energy emission in the near-infrared (NIR) region is the target for small molecule fluorophores with bioimaging applications. These molecules allow for higher resolution imaging compared to shorter wavelength emitters, but suffer from multiple drawbacks largely related to the Energy Gap law. Unique approaches to circumvent such drawbacks are investigated using a combination of photoluminescence and femtosecond transient absorption spectroscopy (fsTAS). Finally, a series of donor-bridge-acceptor (D-B-A) molecules with charge-transfer capabilities are presented in the context of their use in dye-sensitize solar cells (DSCs). Solar energy capture is a pressing goal as the world shifts from fossil fuels to clean, renewable energy generation. Using fsTAS, the structure function relationship of dyes with DSC applications is probed. Specifically, the effects of proaromaticity in the bridging unit is investigated through a combination of both quantum computational and photophysical data.

Available for download on Wednesday, August 16, 2023

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