▎ 摘　　要

A doable, low cost, green and scalable method is demonstrated to synthesize N-doped graphene/CNTs composite using humic acid (HA) and urea via ball mill technique. The structural characterizations were investigated by scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD). SEM investigations reveal a highly porous morphology of the synthesized powder. It was also observed that, some carbon nanotubes were unzipped as well as completely opened CNTs due to the synthesis process. Additionally, this study found that urea and HA crucially impacted synthesis process. N-doping was confirmed by EDX measurements and a remarkable enhancement in surface area was detected using surface area sorption (BET) analyzer. The presented method is very practical and can be scaled up for industrial applications with recyclable materials. By optimizing the preparation conditions, it is possible to achieve a significant impact toward enhancing the desired properties of the synthesized nanocomposite. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Ain Shams University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).