Nanofibers modified through carbon and nitrogen co‐doping and phase transformation for application in pseudocapacitors

Summary Nitrogen and carbon‐codoped titanium dioxide nanofibers (N,C‐TiNF) were prepared through a feasible and cost‐beneficial electrospinning procedure and introduced as active materials for electrodes in supercapacitors. The influence of nanofibers modification by nitrogen doping was demonstrated on the performance of supercapacitors. In addition, it was shown that the carbon originating from the fiber precursor could be doped on TiNF with no need for a carbon doping agent. The C‐doped TiNF (C,TiNF) was also compared with the N,C‐TiNF to explore the change in the behavior of supercapacitors. The specific capacitance of the prepared N,C‐TiNF electrode (102 F g−1) was found to be four times more than that of the C‐TiNF electrode (25 F g−1) in an Na2SO4 2 M solution. With nitrogen doping on the surface of the C,TiNF, the lattice anatase phase changed to rutile, and the distance between the (O‐2p) valence and conduction bands (Ti‐3d) reduced. As a result, the pseudocapacitance properties were enhanced. It is generally concluded that N, C‐TiNFs are excellent candidates to be applied in supercapacitors. Nitrogen and carbon‐codoped titanium dioxide nanofibers (N,C‐TiNF) were prepared through a feasible and cost‐beneficial electrospinning procedure and introduced as active materials for electrodes in supercapacitors. The specific capacitance of the prepared N,C‐TiNF electrode (102 F g−1) was found to be four times more than that of the C‐TiNF electrode (25 F g‐1) in an Na2SO4 2 M solution.