Electrospun lignin-based twisted carbon nanofibers for potential microelectrodes applications

Lignin nanofibers (NFs) have been fabricated by electrospinning of a new formulation system: lignin, polyvinyl alcohol (PVA), dimethyl sulfoxide (DMSO) mixture. The ternary phase diagram of this system has been realized in order to define bead free nanofibers electrospinnability domains. Resulting NFs mat were carbonized in a temperature range 550–1200 °C and then characterized by X-Ray diffraction, Raman spectroscopy, and electrochemical measurements. It revealed the influence of the carbonization temperatures on the structural properties in the resulting CNFs. Lignin NFs yarns have been for the first time manufactured by twisting the initial electrospun lignin NFs precursor mats. The structure and properties of the obtained lignin-based twisted carbon nanofibers (TCNFs) have been characterized as function of the degree of twist. Electrochemical capacitance and electrical conductivity of the TCNFs have revealed the influence of an increase in the twisting level (from 330 mF.g−1 to a few mF.g−1 and from 11 to 22 S.cm−1). It has been established that the compaction and the densification of highly TCNFs yarns are the reasons of these electrochemical and electrical behaviors. Manufactured bio-resourced conductive TCNFs yarns can be promising candidates as microelectrodes in biosensor or biofuel cells applications.