Optimizing the Pore Structure of Bio-Based ACFs through a Simple KOH–Steam Reactivation

Highly microporous bio-based activated carbon fibers (ACFs) were prepared through a simple reactivation method. Sawdust, as the starting material, was liquefied and melt-spun to produce the precursor fibers. Then, the precursor fibers were activated by KOH and reactivated by steam. By varying the conditions of the two activation processes, the formation mechanism of the pore structure was studied, and the result showed that steam reactivation has a positive effect on the development of microporosity. The sample with the optimal condition exhibited the highest specific surface area of 2578 m(2)·g(−1) as well as the largest pore volume of 1.425 cm(3)·g(−1), where micropores contributed 70.3%. Due to its excellent texture properties, the ACF exhibited a high adsorption capacity of 1934 mg/g for iodine.