Organic Solvent-Assisted Lyophilization: A Universal Method of Preparing Two-Dimensional Material Nanoscrolls

Abstract

Rolling up two-dimensional (2D) materials into one-dimensional (1D) nanoscrolls is a straightforward way to fabricate 1D nanomaterials, which can inherit the properties from 2D materials and exhibit new functions originated from 1D morphology. Here, we report a general and facile method for preparing nanoscrolls: organic solvent-assisted lyophilization (OSAL). High-quality nanoscrolls from different 2D materials, including graphene oxide, reduced graphene oxide, and MoS 2 , can be obtained by lyophilizing their aqueous dispersion in the presence of a small volume of high-boiling-point organic drying. Mechanism investigation reveals that the imbalanced surface tension on the two sides of the 2D material sheet caused by the absorbed organic solvent is the driving force of the rolling up process. OSAL can also be used to produce composite nanoscrolls by encapsulating other nanomaterials into the inner space of nanoscrolls, even the nanomaterials that show weak infinity for the 2D material. The produced reduced graphene oxide nanoscrolls can form a nonwoven fabric, which shows high performance as a flexible electrode of a supercapacitor. The OSAL method developed here opens a new route for fabricating novel 2D-material-based nanostructures and offers a novel platform for designing and preparing 1D nanomaterials.