Adsorption is one of the effective technologies in the field of water purifying. In order to improve the adsorption rate, the adsorbents having high specific surface area and rapid mass transfer are required. Carbon nanofibers have been widely applied due to their great technological and industrial importance. Especially, the hollow carbon nanofibers have attracted much attention due to their large specific surface area, relatively uniform and shallow pores, enhancing adsorption rates and efficiency of transport processes both within and across the nanotube walls.  In this work, hollow porous carbon nanofibers (HCNFs) were prepared by stabilization, carbonization and activation of coaxially electrospun nanofibers where immiscible polymer solutions produced nanofibers with core/shell structures. Two viscous liquids were simultaneously fed through the inner (core, containing poly(methyl methacrylate) (PMMA)) and outer (shell, containing polyacrylonitrile (PAN) solution) capillaries, respectively. The samples were characterized using several techniques, including the field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), and N<sub>2</sub> adsorption/desorption isotherms.  Results showed that the sacrifice core (PMMA) could be removed at the selected carbonization temperatures and the carbon nanofibers with hollow structure were obtained. The HCNFs with about 560 and 750 nm for core and shell diameters showed excellent microporous structure, exhibiting a specific surface area of 625 ~ 756 m<sup>2</sup>/g. The ratios of micropore area to specific surface area could achieve 0.88. Especially high percent of pore volume in ultramicropore (&lt; 0.7 nm) range was observed (47 ~ 56 %). The nitrogen contents of the HCNFs ranging from 1.6 ~ 7.2 at. % decreased with increasing carbonization temperatures. It was found that higher carbonization temperature would give out mostly the nitrogen-containing functional groups at lower binding energies.

Preparation and characterization of hollow porous carbon nanofibers

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.