Valorization of petroleum coke into high-quality few-layer graphene through liquid-phase exfoliation
Abstract
Low-value fuel-grade petroleum coke (petcoke), an abundant byproduct from petroleum refining operations, is traditionally used in low-value fuel and metallurgical applications owing to its high carbon content and ability to be used in the synthesis of advanced carbon materials. In this paper, we demonstrate a non-oxidation-based route for producing conductive few-layer graphene from petcoke through sequential isopropanol assisted pre-treatment, thermal desulfurization, and CO ₂ assisted liquid phase exfoliation. Unlike conventional graphene synthesis processes using high temperature chemical vapor deposition, oxidation reduction-based Hummer’s type methods, or exfoliation from expensive graphite sources, our approach enables the conversion of inexpensive petcoke into graphene nanosheets using a scalable solvent assisted route. Thermal treatment increased the graphitization degree of petroleum coke to approximately 78%, demonstrating its potential as a precursor for advanced graphitic materials. The optimized CO₂-assisted liquid-phase exfoliation and centrifugation procedure achieved approximately 90% recovery of dispersed exfoliated carbon solids. Combined optical microscopy, Raman, TEM, HRTEM, AFM, and electrical analyses confirmed the formation of well-dispersed, conductive few-layer graphene nanosheets, with thicknesses corresponding to approximately 3–5 layers. The graphene dispersions display stability up to six months and can be transformed into conductive films with a maximum electrical conductivity of 872 S m⁻ ¹ after thermal annealing. This work establishes petcoke as a promising low-cost carbon resource for sustainable graphene production and offers a practical route for transforming refinery waste into value-added materials for energy storage, conductive coatings, composites, and carbon-based technologies.
Versions
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BibTeX
@article{alkahtani2026valorization,
title = {{Valorization of petroleum coke into high-quality few-layer graphene through liquid-phase exfoliation}},
author = {Masfer H. Alkahtani and Yahya A. Alzahrani and Abdulmalik M. Alessa and Abdulaziz Alromaeh and Majed M. Aljomah and Faisal Alghannam and Fahad H. Albaqami and Anas Almuqhim and Abdulaziz Aljuwayr and Ramu Banavath and Micah J. Green and Philip R. Hemmer},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-74440-4},
url = {https://www.nature.com/articles/s41598-026-74440-4},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Valorization of petroleum coke into high-quality few-layer graphene through liquid-phase exfoliation
AU - Masfer H. Alkahtani
AU - Yahya A. Alzahrani
AU - Abdulmalik M. Alessa
AU - Abdulaziz Alromaeh
AU - Majed M. Aljomah
AU - Faisal Alghannam
AU - Fahad H. Albaqami
AU - Anas Almuqhim
AU - Abdulaziz Aljuwayr
AU - Ramu Banavath
AU - Micah J. Green
AU - Philip R. Hemmer
PY - 2026
DA - 2026/10/07
JO - Scientific Reports
DO - 10.1038/s41598-026-74440-4
UR - https://www.nature.com/articles/s41598-026-74440-4
AB - Low-value fuel-grade petroleum coke (petcoke), an abundant byproduct from petroleum refining operations, is traditionally used in low-value fuel and metallurgical applications owing to its high carbon content and ability to be used in the synthesis of advanced carbon materials. In this paper, we demonstrate a non-oxidation-based route for producing conductive few-layer graphene from petcoke through sequential isopropanol assisted pre-treatment, thermal desulfurization, and CO ₂ assisted liquid phase exfoliation. Unlike conventional graphene synthesis processes using high temperature chemical vapor deposition, oxidation reduction-based Hummer’s type methods, or exfoliation from expensive graphite sources, our approach enables the conversion of inexpensive petcoke into graphene nanosheets using a scalable solvent assisted route. Thermal treatment increased the graphitization degree of petroleum coke to approximately 78%, demonstrating its potential as a precursor for advanced graphitic materials. The optimized CO₂-assisted liquid-phase exfoliation and centrifugation procedure achieved approximately 90% recovery of dispersed exfoliated carbon solids. Combined optical microscopy, Raman, TEM, HRTEM, AFM, and electrical analyses confirmed the formation of well-dispersed, conductive few-layer graphene nanosheets, with thicknesses corresponding to approximately 3–5 layers. The graphene dispersions display stability up to six months and can be transformed into conductive films with a maximum electrical conductivity of 872 S m⁻ ¹ after thermal annealing. This work establishes petcoke as a promising low-cost carbon resource for sustainable graphene production and offers a practical route for transforming refinery waste into value-added materials for energy storage, conductive coatings, composites, and carbon-based technologies.
SN - 2045-2322
ER -