Biomimetic construction and preparation of high-strength carbon‑carbon composites reinforced with highly disordered nanocrystalline graphite and reduced graphene oxide

With the wide application of graphite products, the low strength has become a key influencing factor hindering the application of the functionalized graphite. Taking inspiration from the phenomenon of the pericarp preventing fruit cracking in nature, we proposed a biomimetic structure based on the pomegranate, and successfully fabricated a pomegranate-like carbon‑carbon composite (PL-C/rGO-1700) at 1700 °C by spark plasma sintering (SPS), using nanodiamonds and graphene oxide (GO) as precursors, respectively. The disordered nanocrystalline graphite derived from nanodiamonds and the reduced graphene oxide (rGO) can be considered as "pomegranate seeds" and "membrane", respectively. The addition of rGO effectively deflected the crack extension path to enhance the flexural strength of the samples. Moreover, nanodiamond-derived disordered stacked nanocrystalline graphite improved the hardness, Young's modulus, and indentation elastic recovery of graphite bulk materials. The obtained PL-C/rGO-1700 exhibited a microhardness, flexural strength, indentation elastic recovery rate, and compressive strength of 2.7 GPa, 78.1 MPa, 81.0 %, and 259.0 MPa. Therefore, our work provided a simple and rapid method for the preparation of high-strength carbon‑carbon composites.