Author ORCID Identifier
https://orcid.org/0000-0002-5063-340X
Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Katharine M. Tibbetts
Abstract
Metal-carbon nanomaterials are incredibly versatile with applications spanning from energy storage to biomedical devices. However, there are currently very few environmentally friendly techniques for the synthesis of these desirable materials. Many traditional synthesis techniques produce large amounts of chemical waste and consume excessive energy through the use of harsh conditions and toxic chemicals. Laser synthesis is able to overcome the challenges faced by traditional synthesis techniques by synthesizing desirable materials in a much more environmentally friendly manner and on much quicker time scales. Of particular interest in the synthesis of metal-carbon nanomaterials is the laser technique of laser reduction in liquid (LRL). LRL is a reactive laser technique that uses non-equilibrium chemistry to synthesize very small nanoparticles with a uniform size distribution. In LRL, the laser induces decomposition of the liquid producing solvated electrons, radicals, and various reactive species without the use of surfactants, capping ligands, and toxic reducing agents. The lack of these chemical species limits the amount of chemical waste produced. Due to the nature of LRL reducing the liquid media during reaction, it is important to understand how the liquid itself reacts under laser irradiation.
When water is irradiated with laser pulses a weakly ionized plasma is made, leading to the formation of H. and OH. radicals in solution. Pulsed laser excitation of liquid organic media is not as well characterized because irradiation of the neat solvent can lead to the formation of products in the gas, liquid, and solid phase. As a result, an in-depth study of the neat organic solvents used in the nanomaterial generation process is of importance if we want to understand the processes that occur to better synthesize desirable materials.
In this work, we seek to gain insight into how organic solvents decompose under laser irradiation and the reactive species that are produced. Due to the complexity of organic solvents behavior under laser irradiation, studying the reaction mechanism for these processes is incredibly complex. Here we use strong-field ionization mass spectrometry and gas chromatography paired with mass spectrometry to study the fragmentation patterns of organic solvents in the gas phase and the resulting liquid species that are produced. In order to understand the rate of reaction of these solvents under laser irradiation we utilize UV-visible spectroscopy to gain kinetic insight and transient absorption spectroscopy to track the movement of solvated electrons in solution. Three studies will be detailed here. In the first, the hexane isomers n-hexane, 2-methylpentane, and 3-methylpentane were studied and we found that each makes distinct products that depend on the geometric structure. Next, we utilized iodine as a radical scavenger in order to resolve highly reactive and short-lived radicals of 2,3-dimethylbutane. Finally, we applied what was learned in these solvent studies and added nickelocene to the solution to produce an electrocatalyst that holds potential in the oxygen reduction reaction.
Rights
© Ella Kaplan
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-8-2026