Porous materials with the advantages of high specific stiffness, high specific strength and strong energy absorption can be used in the fields of composite materials, environment, energy and biology. The construction of ultra-lightweight materials with densities below 10 mg/cm3 is currently a hot topic of international research, such as metal and ceramic-based superlattices. However, as the density decreases, the mechanical and electrical properties of these materials decrease exponentially, while the stability of the material structure and the recoverable deformation deteriorate significantly. Scientists dream of carbon-based porous materials, consisting of carbon nanotubes or graphene, that combine excellent mechanical and electrical properties. This requires that the structural units (between carbon tubes or graphene sheets) be connected by covalent bonds, but this is difficult to achieve.
  
  Recently, in a collaborative study between the Shanghai Institute of Silicate, Chinese Academy of Sciences, the University of Pennsylvania and Peking University, Bi Hui, Chen Yiwei and Huang Fuqiang have discovered a three-dimensional graphene tube "super material", which is a new type of porous material with a hierarchical porous structure, combining strong mechanical, low density and high It is a new type of porous material with a hierarchical porous structure. The three-dimensional graphene is composed of four connected graphene nanotubes bonded by carbon-carbon covalent bonds for the first time, forming a diamond-like four-ligand three-dimensional solid structure.
  
  The three-dimensional graphene tubes have high strength and can support 40,000 times their own weight without significant deformation, and also have ultra-high elasticity with almost complete recovery after 1000 cycles, the most of all porous materials. The graphene hollow tube material has excellent electrical conductivity, and the 3D graphene tube can be used as an elastic conductor with excellent performance, and its mechanical and electrical properties are 1-2 orders of magnitude higher than those of the currently reported porous graphene, which can be applied in new energy fields. In addition, the material has super hydrophobic properties, adsorbs organic solvents super fast, adsorbs organic solvents up to 600 times its own weight or more, and can be used in sewage treatment, such as offshore oil spills.