Fabrication of Porous Carbon-Composite Nanofibers Via Electrospinning and Their Application in Ion Storage System

Abstract

Nanoporous materials have attracted considerable attention for various potential applications in sensors, optical, magnetic and electronic devices due to their high specific surface area and distinctive physicochemical properties. Particularly, porous carbon-composite materials can be used in the field of catalysis, separation, purification, capture and energy storage/conversion systems. In this work, we prepared highly porous carbon-composite nanofibers with hollow-structures by electrospinning combined with hundreds of nanometers sized silica nanoparticles and 2D MXene flakes and demonstrated the applications in ion storage systems. Firstly, nanoparticles and MXene flakes embedded-polyacrylonitrile(PAN) was electrospun with single and dual nozzles, respectively. In the case of electrospinning via dual nozzle , PAN/Mxene solution and polymethyl methacrylate (PMMA) solution were used as shell and core materials, respectively. After the electrospinning process, the nanofibers were stabilized at 280oC, followed by a carbonization at 800oC for 1h. Selective removal of silica nanoparticles by HF solution after the carbonization and the decomposition of PMMA at 400oC resulted in the well defined hollow-structured carbon-composite nanofibers. The morphologies of the nanofibers depends on the concentration and size of silica nanoparticles and Mxene flakes and the each specific surface area was higher about 6 and 7 times than those of normal carbon nanofibers. Particularly, the carbonization of MXene-embedded nanofibers successfully removed the functional groups on the MXene such as –F and –OH which are known to hinder Li-ion transport. The hollow structured carbon composite nanofibers with tailored surface terminations and the increased specific surface area were utilized as a electrode materials of ion storage systems and showed improved electrochemical performance compared to normal carbon nanofibers or carbon-MXene composite paste. Figure 1