Abstract

 Graphene‐based hybrid carbons composed of a mix of AB‐stacked and turbostratic regions are reported. Macroscopic graphene films consisting of stacked graphenes are prepared using a liquid crystal graphene oxide dispersion. The graphene films are then infiltrated with bioinspired adhesives, catecholamines, and polymerized to obtain graphene/poly(catecholamine) composites. After heat treatment up to 3000 ºC, the composite films are transformed to have both AB‐stacked (mainly from graphene oxide) and turbostratic (mainly from poly(catecholamines)) structures, and exhibit significantly improved mechanical properties compared to the films having a predominant AB‐stacked structure made from only graphene oxide. They have almost twice the fracture strength (1012 ± 146 MPa) and ≈1.5× increase of both Young's modulus (21.87 ± 2.24 GPa) and strain‐to‐failure (8.91 ± 0.50%). In addition, the films have an in‐plane electrical conductivity as high as 1320 ± 159 S cm^​-1. Such hybrid‐carbon films with the indicated mechanical and electrical properties have many promising uses, such as for light‐weight structural materials, and in flexible electronics such as for wearable heaters or in sensing electrodes.