context: The preparation of N-doped carbon nanofibers decorated with Mo2C quantum dots (Mo2C@NCF) is illustrated in Scheme 1. Mo2C@NCF was first fabricated via an electrospinning technology followed by a high-temperature annealing process. Afterwards, facile glow discharge plasma (GPD) was employed on the surface of Mo2C@NCF. Fig. 1a shows the XRD patterns of as-prepared Mo2C@NCF and GDP-Mo2C@NCF. The diffraction peaks of both Mo2C@NC and GDP-Mo2C@NC are in good agreement with that of hexagonal Mo2C (JCPDS 35-0787) without any impurity peaks, suggesting the high purity of Mo2C. After high energy glow plasma treatment, all the characteristic peaks become stronger. As shown in the SEM and TEM images (Fig. 1b and c), Mo2C@NCF displays a fibrillar structure with a smooth surface and an average diameter of ∼100 nm, and the one-dimensional orientation benefits fast transport of electrons/ions. The HRTEM images show the distribution of Mo2C quantum dots with an average diameter of 3–4 nm encapsulated in the carbon fiber though there are no lattice fringes (Fig. 1d and e). Different from that of Mo2C@NCF, the surface of GDP-Mo2C@NCF is etched using the high energy particles during the plasma process, leading to a rough appearance and exposure of Mo2C quantum dots (Fig. 1f and g). This morphological change offers a large electrode–electrolyte contact area to ensure high availability of catalytically active sites. The HRTEM images clearly demonstrate the presence of Mo2C quantum dots, and an observed lattice fringe spacing of 0.24 nm corresponding to the (101) plane of Mo2C (Fig. 1h and i). The EDX mapping images confirm the uniform distribution of C, N and Mo elements on the carbon fiber (Fig. 1j).