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

Adv Mater. 2024 Apr 26:e2402628. doi: 10.1002/adma.202402628. Online ahead of print.

Abstract

We report a new nanoporous amorphous carbon (NAC) structure that achieves both ultrahigh strength and high electrical conductivity, which are usually incompatible in porous materials. By using modified spark plasma sintering, we create three amorphous carbon phases with different atomic bonding configurations. The composite consists of an amorphous sp2-carbon matrix mixed with amorphous sp3-carbon and amorphous graphitic motif. NAC structure has isotropic electrical conductivity of up to 12,000 S/m, a 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 (TEM), electron energy loss spectroscopy (EELS), 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. Our research not only introduces novel material with exceptional properties, but also opens new opportunities for exploring amorphous structures and designing high-performance materials. This article is protected by copyright. All rights reserved.

Keywords: (sp2‐sp3 mixed amorphous carbon; electrical conductivity; high strength nanoporous structure); multiphase composites.