Synthesis and Characterization of MXene/Graphene Composite with Porous Structure

Abstract

Two-dimensional (2D) nanomaterials for example graphene have become a versatile platform for the fabrication of innovative hybrid materials with various functions due to their unique electrical, optical, thermal, and mechanical properties. Combining graphene with other materials to prepare composites with nanoscale precision is highly important and desirable for reproducible and controllable performance through self-assembling. However, in order to fabricate composite materials with unique structures for example porous structure using 2D materials, the restacking and aggregation issues need to be addressed. In this project, a self-assembled MXene/ graphene composites with controllable porous structure were prepared using ice as template. The addition of graphene plays an important role on the formation of MXene based porous structure with well-defined and interconnected network. The evolution of the nanostructure of the MXene/graphene composites was controlled by varying the weight ratio between graphene and MXene. Various characterization methods, for example, SEM, EDX, XRD, Raman, and FTIR were then used to understand the structure–property relationships of the porous composites. From the 4-point probe measurements, we found that although the graphene can facilitate the formation of porous structure, the electrical conductivity of the porous MXene/- graphene composites decreased as more graphene was added. Therefore, the ratio between graphene and MXene need to be balanced in order to obtain the composites with both high porous structure and high conductivity. Such simple freeze-drying method could not only allow us to prevent the serious aggregation of 2D material during self-assembling, but also prepare composite with unique structures in large scale.