Loops at carbon edges: Boron-assisted passivation and tunable surface properties of carbon nanofibers

During thermal treatment of carbon materials, unstable edge sites can easily convert to structurally stable loop structures. Hence, in the present work, carbon edges are physically passivated via high-temperature treatment in the presence of boron atoms to accelerate loop formation. The highly accelerated loop formation, along with stacking multi-layers at the carbon edges, is systematically investigated via high resolution transmission electron micro microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and thermal gravimetric analysis (TGA). The boron-added carbon nanofibers (CNFs) at high temperature exhibit a greatly enhanced electrical conductivity due to the high mobility of boron atoms within the carbon structure. In particular, engineering of the loop structures on the carbon edges can alter the overall electrocatalytic activities of the carbon-based materials, as demonstrated in the reductive conversion of 4-nitrophenol (4-NP) and in the hydrogen evolution reaction (HER). This work not only suggests suitable methods for carbon edge passivation, but also opens up a route towards the advanced design of high-stability carbon materials in various fields.

Automated summary

In this study, carbon edges were physically passivated through high-temperature treatment with boron atoms, leading to the formation of stable loop structures. The boron-added carbon nanofibers exhibited enhanced electrical conductivity and electrocatalytic activities. This research provides suitable methods for carbon edge passivation and offers new directions for advanced design of high-stability carbon materials in various fields.