Synergistic mechanochemical and thermal treatment for enhancing the structure and textural properties of petroleum coke-derived carbon materials

This study investigated the synergistic effects of mechanochemical processing (dry and wet ball milling) and controlled thermal treatment on the structural and textural properties of petroleum coke (petcoke). Petcoke samples were subjected to ball milling, followed by pyrolysis at 400–700 °C under a nitrogen atmosphere. X-ray diffraction revealed a significant reduction in crystallinity after milling with partial graphitic reordering at elevated pyrolysis temperatures. Scanning electron microscopy and particle size analysis confirmed the reduced particle size and improved morphological uniformity, particularly in wet-milled samples. Transmission electron microscopy further revealed enhanced nanoscale disorder, the presence of turbostratic domains, and partial graphitization. Surface and chemical analyses (EDX, FTIR, and Raman) indicated improved carbon purity and the effective removal of oxygen- and sulfur-containing functional groups. Notably, texture analysis based on nitrogen adsorption/desorption measurements (BET analysis) showed substantial improvement in textural characteristics, including an increase in surface area from 2.0 m²/g (dry-milled) to 42.7 m²/g (wet-milled), increased micropore volume, and preserved microporosity. Thermogravimetric analysis demonstrated improved thermal stability across all treated samples. The combination of wet ball milling and pyrolysis at 700 °C yielded the most favorable structure–texture synergy. These findings highlight the effectiveness of integrating solvent-assisted ball milling with thermal activation as a scalable strategy for converting petcoke into porous activated carbon with a tailored structure, texture, and surface properties. This synergistic approach provides valuable insights into the future development of functional carbon materials.