Activated carbon fiber derived from the seed hair fibers of Metaplexis japonica: Novel efficient adsorbent for methylene blue

Abstract

Activated carbon fiber (ACF) has broad application prospects in dyeing wastewater purification owing to its high specific surface area and hierarchical pore distribution. Natural fiber based ACFs is a group of emerging biomass adsorbent with attractive potential adsorbent properties. Herein, we develop a facile carbonization strategy to obtain a novel biomass ACF derived from the seed hair fibers of metaplexis japonica (MACFs), and the prepared MACFs possess hollow structure and the formation of graphite-like crystallites from MACFs is promoted by high temperature of carbonization. MACFs possess well-developed pore distribution, with a maximum specific surface area and total pore volume of 1882.003 m2/g and 1.613 cm3/g, respectively. MACFs exhibits the maximum adsorption capacity to be 943.372 mg/g for methylene blue (MB) fitting well with Langmuir model. Furthermore, MACFs can adsorb full solution of 90 mg/l by filtering only one time, proving its fast-adsorption performance. The high adsorption capacity and speed of MACFs are mainly attributed to three factors: high specific surface area and rich pores benefited from the full activation of hollow fibers, strong electrostatic attraction to MB provided by surface groups, and good contact with dye liquor. This work may shed light of the adsorption mechanism of biomass ACFs for the dyeing molecules and pave the way for the development of low-cost and highly efficient adsorbent.