Engineering a Hierarchy of Disorder: A New Route to Synthesize High-Performance 3D Nanoporous All-Carbon Materials*

A new nanoporous amorphous carbon (NAC) structure that achieves both ultrahigh strength and high electrical conductivity, which are usually incompatible in porous materials is reported. By using modified spark plasma sintering, three amorphous carbon phases with different atomic bonding configurations are created. The composite consisted of an amorphous sp²-carbon matrix mixed with amorphous sp³-carbon and amorphous graphitic motif. NAC structure has an isotropic electrical conductivity of up to 12 000 S m^-1, Young's modulus of up to ≈5 GPa, and Vickers hardness of over 900 MPa. These properties are superior to those of existing conductive nanoporous materials. Direct investigation of the multiscale structure of this material through transmission electron microscopy, electron energy loss spectroscopy, and machine learning-based electron tomography revealed that the origin of the remarkable material properties is the well-organized sp²/sp³ amorphous carbon phases with a core-shell-like architecture, where the sp³-rich carbon forms a resilient core surrounded by a conductive sp²-rich layer. This research not only introduces novel materials with exceptional properties but also opens new opportunities for exploring amorphous structures and designing high-performance materials.