In situ formation of electrospun graphene nanofibers

Abstract Graphene-based materials are currently in the focus of research, but toward any application a simple and reliable fabrication process is mandatory. To date, graphene nanofibers (GNF) made via electrospinning have been established, using graphene oxide (GO) as templating agent. However, relying on GO as a solid insoluble precursor makes the process harder. We present a method to produce in situ neat GNFs made of solely electrospun polyacrylonitrile (PAN). Besides heating in an oven up to 1700 $$^{\circ }\text {C}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mo>∘</mml:mo> </mml:mmultiscripts> <mml:mtext>C</mml:mtext> </mml:mrow> </mml:math> , the GNFs were heated by self-resistive heating. For this the nanofibers were placed into an electrical circuit and a rising electrical power was applied reaching over 3200 $$^{\circ }\text {C}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mo>∘</mml:mo> </mml:mmultiscripts> <mml:mtext>C</mml:mtext> </mml:mrow> </mml:math> directly in the nanofibers. The Raman, XPS, and XRD results show high crystalline GNFs, with little to no defects and high graphitization degree. Furthermore, the electrical transport measurements revealed an eightfold increase in the conductivity. The deeper analysis of the 2D-band indicates the graphene structure. This simple way of electrospun GNFs with a commonly used polymer precursor opens the door to easier access and broader functional application of said nanofibers.