Self-template synthesis of hierarchical magnetic porous carbon fibers derived from Fe(BTC)-coated bamboo fibers for fast removal of methylene blue

Abstract

Hierarchical magnetic porous carbon fibers (MBFs) were fabricated by annealing Fe(BTC)-coated bamboo fibers, which were produced using a new synthesis route for growing Fe(BTC) on bamboo fiber materials, in a nitrogen atmosphere. The materials were characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, Brunauer–Emmett–Teller surface area measurement, and vibrating sample magnetometry. The obtained MBF composites possess both high surface areas and magnetic characteristics. Their adsorption properties were preliminarily tested by the adsorptive removal of methylene blue from aqueous solution. Results demonstrated that the obtained hybrid materials possess high adsorption capacity and can be easily recycled from liquid media by using an external magnetic field. MBF adsorption reached equilibrium within approximately 1 min and the adsorption capacity rapidly reached 143 mg g⁻¹. Most importantly, MBF can be reused after washing with ethanol. After six reuses, the removal efficiency could still reach 80%. Moreover, the low-cost raw material used (i.e., bamboo) is abundant and renewable. This study indicated that the as-prepared MBF composites show great potential for use in a wide range of applications.