Doctoral Dissertations

Keywords and Phrases

Biochar; Exfoliation; Graphene; Graphite; Ultrasonic

Abstract

The synthesis of high-quality graphene from sustainable carbonaceous feedstocks offers an avenue to reduce the environmental and economic costs associated with conventional graphite-based production. This research investigates the co-utilization of biochar and graphite as precursors for graphene fabrication in an ultrasonic reactor. Biochar was produced from biomass via downdraft gasification at 850 °C, yielding a high fixed-carbon, partially graphitized material with favorable surface area and porosity. Graphite, selected for its crystalline structure, was investigated with biochar to assess the influence of precursor composition on exfoliation efficiency, layer thickness distribution, and defect density. Ultrasonic-assisted liquid-phase exfoliation was employed, with process parameters like acoustic power, frequency, residence time, and solvent medium are systematically optimized to balance yield and structural integrity. The resulting graphene was characterized using Raman spectroscopy, X-ray diffraction, scanning electron microscopy, and BET surface area analysis to establish correlations between feedstock properties and product quality. Findings indicate that graphite can produce few- layer graphene with tunable surface functionalities. This study demonstrates a viable pathway for exploring the use of both renewable biomass-derived carbon and graphite into advanced nanomaterial production, aligning graphene manufacturing in an Ultrasonic Reactor with principles of resource efficiency and environmental sustainability.

Advisor(s)

Smith, Joseph D.

Committee Member(s)

Ludlow, Douglas K.
Gelles, Gregory M.
Al-Rubaye, Haider
Okoronkwo, Monday Uchenna
Al-Dahhan, Muthanna H.

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2025

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 10–51, has been published in Fuels.

Paper II, found on pages 52–89, has been submitted for publication in Fuels.

Paper III, found on pages 90–118, has been submitted for publication in Fuels.

Paper IV, found on pages 119 – 181, has been submitted for publication in Chemical Engineering and Processing – Process Intensification.

Pagination

xvi, 188 pages

Note about bibliography

Includes_bibliographical_references_(pages 186-187)

Rights

© 2025 Paul Chukwuma Ani , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12554

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