In-Situ Carbon [Graphene]-Modified TiO2 Nanofiber and Aerogel Materials: Development, Characterization, and Energy Relevant Applications

Author

• Alexa Villarreal, The University of Texas Rio Grande Valley

Date of Award

5-1-2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Materials Science and Engineering

First Advisor

Ahmed Jalal

Second Advisor

Karen Lozano

Third Advisor

Victoria Padilla

Abstract

The development of advanced material platforms capable of addressing rising atmospheric carbon dioxide (CO₂) levels requires not only catalytic functionality but also deliberate structural and interfacial design. Titanium dioxide (TiO₂) has been widely investigated as a semiconductor for photocatalytic and electrochemical processes; however, limitations including rapid charge recombination and nanoparticle agglomeration restrict its performance. Structural engineering across multiple dimensional architectures provides a promising strategy to overcome these limitations by enhancing surface accessibility, charge transport, and interfacial interactions.

This dissertation investigates process-induced confinement as a governing parameter in the structural evolution of nanofibrous architectures fabricated through centrifugal spinning platforms. Melt-ForceSpinning® (MFS) and solution ForceSpinning® (FS) are explored as complementary fabrication routes for generating hierarchical materials ranging from porous polymer scaffolds to semiconductor–carbon hybrid systems. Melt-processed immiscible polymer blends are utilized to produce porous fibrous frameworks through sacrificial phase extraction, while solution-based spinning enables the incorporation of titanium precursor systems for the formation of confined TiO₂ nanostructures. Subsequent thermal treatments and in-situ graphene formation introduce conductive interfaces that enhance charge separation and transport behavior.

Through comparative analysis of embedding and surface-coating strategies, this work demonstrates how processing route, dimensional confinement, and interfacial engineering collectively influence structural organization within nanofibrous materials. The resulting hierarchical architectures provide insight into the design of scalable platforms with potential relevance to catalytic, environmental, and energy-related applications. Accordingly, this dissertation is organized into two primary sections based on the spinning approach employed: Section I focuses on solution-based spinning systems and includes Chapters II and III, while Section II focuses on melt-ForceSpinning® approach and includes only Chapter IV.

Comments

Copyright 2026 Alexa Villarreal. All Rights Reserved. https://proquest.com/docview/3371171833

Recommended Citation

Villarreal, A. (2026). In-Situ Carbon [Graphene]-Modified TiO2 Nanofiber and Aerogel Materials: Development, Characterization, and Energy Relevant Applications [Doctoral dissertation, The University of Texas Rio Grande Valley]. ScholarWorks @ UTRGV. https://scholarworks.utrgv.edu/etd/1938