Prediction index of final activated carbon performance: the regulation of mesopore ratio/mesopore volume in biochar precursor

Abstract

Currently, the synthesis of activated carbon predominantly relies on trial and error, specifically centered on the modulation of activators or alterations in activation conditions. However, the resultant characteristics of activated carbon obtained through such procedures normally lacked predictability and control. This study utilized natural pine wood powder as the primary material and three distinct biochar precursors were prepared through meticulous control of oxidation time, possessed similar O/C with varying initial pore structures. Except that, the porosity or mesopore volume were significantly different. Final results showed that precursor materials with higher mesoporous ratios/volumes prefer to hinder the increase of specific surface area during activation. The T600-1.5D exhibits a mesopore ratio of 35.26%, nearly double that of T600-0.5D, yet concurrently displays a relatively modest specific surface area only of 1765.6 m²/g. Finally, our study highlights the intrinsic correlation between the mesoporous ratio or mesoporous volume in biochar precursors and the specific surface area of final activated carbon. These findings provide new insights into targeted, predictable, and controllable activation of carbonaceous materials, offering innovative pathways to address the challenges in developing porous materials.