A simple approach to synthesize high-quality 3D graphene sheet by chemical vapor deposition using cobalt catalyst template

Two-dimensional graphene sheets undergo irreversible sheet agglomeration due to van der Waals forces, leading to suboptimal performance of graphene-based devices. Integration of graphene layers randomly into three-dimensional macroscopic structures, also known as 3D graphene, effectively overcomes this limitation while also introducing versatile functionalization capability in the graphene structure. We present here a unique slurry-based cobalt template approach to grow high-quality 3D graphene sheets by thermal chemical vapor deposition using methane as the carbon precursor. 3D graphene sheets so obtained have 0.13 mm average thickness with tailorable dimensions. Characterisations divulge that the sheets are almost defect-free (ID/IG = 0.02), highly porous and consist of predominantly single layers of graphene (I2D/IG = 2–6) intertwined together in three-dimensional architecture. The pristine 3D graphene, as such, is highly conducting (38.9 S/cm) and offers great application prospects in varied applications. The overall activation energy of the reaction is estimated to be close to 55 kJ/mol. The yield as well as quality of 3D graphene enhances with increasing synthesis temperature. Overall, the present work proposes a simple route to make defect-free, high-quality 3D graphene sheets employing cobalt powder as the catalyst precursor. [Display omitted]