Hybrid chemical and physical activation techniques for engineering hierarchical pore structures in activated carbon for enhanced adsorption performance

Abstract This study explores the synergistic impact of hybrid chemical activation (CA) and physical activation (PA) on creating hierarchical pore structures in activated carbons (ACs) derived from various biomass precursors, aiming to improve adsorption performance of radioactive, non-radioactive and organic pollutants that have harmful effects on the environment and living organisms. The Physicochemical properties were systematically determined for the hybrid activated carbon product by using different techniques. CA using H ₃ PO ₄ and NaOH synergistic with PA via steam pyrolysis above 900°C promotes pore development through dehydration, cross-linking, and etching, resulting in carbons with S BET up to 2000 m²/g. Mathematical modeling, including vector analysis and pore formation equations, elucidates the distinct yet interconnected pathways influencing pore evolution during each activation stage. The micro/mesoporous carbons showed high phenol removal efficiency, achieving a maximum adsorption capacity of 110 mg/g at pH 9.5 and up to 90% removal efficiency, highlighting the importance of pore structure preservation for sustainable performance. The study provides insights into optimizing activation parameters for high-performance, sustainable activated carbons in environmental remediation applications.