Engineering Biomass-Based Activated Carbon through Physical and Chemical Activation: A Systematic Review on Pore Structure and Material Performance

Abstract: Biomass-based activated carbon has attracted widespread attention as a sustainable carbon material due to its abundant availability, renewability, and engineered pore structure. The characteristics and performance of activated carbon are greatly influenced by the type of biomass and the activation strategies used during the synthesis process. This article presents a systematic literature review on the potential of biomass and various activation methods in the production of activated carbon, focusing on the development of pore structure and material performance. The review was conducted on various studies related to physical and chemical activation processes, including activation using steam, CO₂, as well as chemical activation using KOH, H₃PO₄, ZnCl₂, and NaOH. The results of the review indicate that the composition of biomass, particularly the content of lignin, cellulose, and hemicellulose, plays a crucial role in determining carbon yield, thermal stability, and pore evolution during the carbonization and activation processes. Physical activation generally results in stable microporous structures but requires high temperatures and relatively long processing times. In contrast, chemical activation can significantly enhance pore development and specific surface area due to the intensive interaction between the activator and the carbon matrix. Among the various activators used, KOH shows the most effective performance in producing highly developed microporous structures with high surface areas. In addition, the hierarchical pore structure consisting of micropores and mesopores significantly contributes to the adsorption capacity, ion transport, and electrochemical performance of the material. Biomass-based activated carbon shows potential for wide applications in the fields of adsorption, water treatment, energy storage, supercapacitors, and solar energy-based interfacial evaporation systems. Overall, this study emphasizes that activation strategies are the main factor determining the process- structure-property relationship of biomass-based activated carbon in the development of high-performance porous carbon materials for environmental and energy applications.

Keywords: activated carbon, biomass, chemical activation, physical activation, pore structure.