Preparation of well-developed mesoporous activated carbon fibers from plant pulp fibers and its adsorption of methylene blue from solution

[Display omitted] •Plant pulp fibers were used as raw material for preparation of activated carbon fibers (ACFs).•ACFs exhibit mesoporous rate of 72.8%-82.7%, specific surface area of 1688–1825 m2/g and average pore size of 2.53–3.31 nm.•The adsorption capacity of ACFs to methylene blue solution was 367.5–490.9 mg/g.•The adsorption isotherm and kinetic models were investigated. Well-developed mesoporous plant-based activated carbon fibers (ACFs) with paper structure were prepared from plant pulp fibers (cotton, sisal hemp, manila hemp, softwood and bleached softwood) using phosphoric acid activation at 450°C. The structure and performance of ACFs were studied. Results show that ACFs exhibit high mesoporous rate of 72.8%-82.7%, large specific surface area of 1688–1825 m2/g and average pore size of 2.53–3.31 nm. ACFs show relatively high methylene blue (MB) adsorption capacity with 367.5–490.9 mg/g. SHP-ACFs have the largest MB adsorption capacity, the adsorption equilibrium data follows the Langmuir model and the kinetic data could be described by the pseudo-second-order model.