Morphology investigation of porous carbon nanofibers

Abstract

Carbon nanofibers (CNFs) have been used in many applications such as sensors, energy storage and biomedical applications owing to high electronic conductivity and chemical stability of CNFs. Performance of carbon nanofibers are influenced by the physical and chemical properties of nanofibers. Furthermore, morphology, porosity and specific surface area are important properties for several applications including energy storage and sensors. There are several techniques to produce nanofibers including chemical vapor deposition, catalytic synthesis, arc discharge and electrospinning. Controlling surface area and porosity is vital considering the performance of CNFs. In this study, polyacrylonitrile (PAN) nanofibers were produced via two commonly used nanofiber production techniques; electrospinning and centrifugal spinning. The morphology of the polymeric nanofibers was studied by using SEM. Moreover, heat treatment was applied in air and the inert atmosphere to fabricate carbon nanofibers and porous carbon nanofibers. The effect of production technique on the morphology and chemical structure was investigated via SEM and XRD studies. Electrospun PAN/PS nanofibers showed beads on string morphology due to low viscosity of the spinning solution while uniform fibers without defects were obtained by using centrifugal spinning technique. Centrifugally spun PAN nanofibers have rough surface while PAN nanofibers with smooth surface was obtained by using electrospinning technique. PCNFs derived from centrifugally spun PAN/PMMA nanofibers had rough surface with porous structure and XRD analysis proved the amorphous structure of PCNFs.