Activated carbon nanofibers (ACNF) have been successfully prepared using an electrospinning method with coconut shell charcoal (CSC) as a carbon source and poly(vinyl alcohol) (PVA) as a spinning polymer agent. The high voltage of 10 kV was applied for the electrospinning system. The positive electrode of the high voltage power supply was connected to the needle tip, and the grounded electrode was connected to the metallic collector wrapped with an aluminum foil. The dry fibers in the form of a fibrous mat were collected in the aluminum foil. The average pore diameters of the generated fibers for all variables ranging from 2.23 to 3.73 nm corresponding to mesoporous carbon nanofibers. The total pore volumes were ranging from 0.50 to 0.92 cm(3)/g. IACNF-60 had the largest surface area of 1,277 m(2)/g obtained from the use of PVA 12 w/v %, 60 wt% CSC, and the use of iodine treatment before thermal stabilization, carbonization, and activation stages. Methylene blue solution was used as a model for the dye adsorption capacity that followed the Langmuir adsorption model. IACNF-60 also indicated the highest theoretical maximum monolayer adsorption capacity in the amount of 166.7 mg/g. Furthermore, the methylene blue removal ability of IACNF-60 for the third cycle was maintained relatively constant at 96%. (c) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.