Reborn Three-Dimensional Graphene with Ultrahigh Volumetric Desalination Capacity

Adv Mater. 2021 Dec;33(48):e2105853. doi: 10.1002/adma.202105853. Epub 2021 Sep 24.

Abstract

The constructing of 3D materials with optimal performance is urgently needed to meet the growing demand of advanced materials in the high-tech sector. A distinctive 3D graphene (3DG) is designed based on a repeated rebirth strategy to obtain a better body and performance after each round of rebirth, as if it is Phoenix Nirvana. The properties of reborn graphene, namely 3DG after Nirvana (NvG), has been dramatically upgraded compared to 3DG, including high density (3.36 times) together with high porosity, as well as better electrical conductivity (1.41 times), mechanical strength (32.4 times), and ultrafast infiltration behavior. These advantages of NvG make it a strong intrinsic motivation for application in capacitive deionization (CDI). Using NvG directly as the CDI electrode, it has an extremely high volumetric capacity of 220 F cm-3 at 1 A cm-3 and a maximum salt absorption capacity of 8.02~9.2 mg cm-3 (8.9-10.2 times), while the power consumption for adsorption of the same mass of salt is less than a quarter of 3DG. The "Phoenix Nirvana"-like strategy of manufacturing 3D structures will undoubtedly become the new engine to kick-start the development of innovative carbon materials through an overall performance upgrade.

Keywords: capacitive deionization; phoenix nirvana; reborn; three-dimensional graphene.