Fig. 1
Reproduced with permission from [173] Copyright 2019 Wiley
a Major fabrication methods of graphene: Top-down and bottom-up fabrication methods. Principal top-down methods include liquid-phase exfoliation and micromechanical cleavage of graphite. An additional method involves the exfoliation of initially oxidized graphite, leading to GO, which is chemically and/or thermally reduced to graphene. The bottom-up fabrication of graphene is usually performed by epitaxial growth on SiC or chemical vapour deposition, typically on Cu using small molecules, such as methane, as precursors. Reproduced with permission from [174] Copyright 2017 Nature Publishing Group. b SEM (a, c, e) images and TEM images (b, d, f) of nanofibers (a, b), nanofibers-rGO-5 (c, d), and nanofibers-rGO-10 (e, f) with different magnifications