High-value multilayer graphene oxide prepared by catalytic pyrolysis of petroleum tar and applications: Trash to treasure

Petroleum tar (PT), a by-product of heavy oil refining, poses significant environmental challenges due to its high production volume and associated pollution risks. This study presents an innovative approach for the catalytic conversion of PT into multilayer graphene oxide using nickel foam (NiF) as a catalyst at reaction temperatures of 500 °C and 700 °C (G_T/Ni₅₀₀ and G_T/Ni₇₀₀). The process effectively decomposes PT and facilitates the structured rearrangement of carbon atoms into graphene layers. Comprehensive characterization techniques, including SEM-EDS, HRTEM, BET, XRD, XPS, and Raman spectroscopy, confirm the formation of high-quality graphene oxide. The synthesized G_T/Ni₇₀₀ material exhibits remarkable electrochemical performance with a specific capacitance of 3.34F/g. G_T/Ni₅₀₀ shows adsorption capacities of 59.86 mg/g for Pb²⁺ and 56.84 mg/g for Cu²⁺. Life Cycle Assessment reveals a substantial reduction in the carbon footprint, with CO₂ equivalents for G_T/Ni₅₀₀ and G_T/Ni₇₀₀significantly lower than traditional methods, at 17.64 kg/CO_2eq and 14.03 kg/CO_2eq, respectively, representing a reduction of over 50 %. This study not only offers a sustainable pathway for PT utilization but also provides advanced materials with dual utility in electrochemical applications and heavy metal adsorption, contributing to environmental remediation and reducing reliance on non-renewable resources.