3D Printing of 3D Graphene—Material Characterization, Properties, Applications and Post Processing to Enhance the Properties

Over the years multiple efforts resulted in the development of various versions of 3D Graphene via chemical and non-chemical routes. 3D printing of graphene-based polymer inks and aerogels has been considered efficient and promising among the other processes given the advantages of this approach. However, the resultant 3D graphene structures highly rely on a binder or ice support to stay intact. The presence of a binder or another non-graphene phase hinders the translation of the excellent graphene properties into the 3D structure. Here we report 3D-shaped 3D graphene (3D²G) synthesized by combining 3D printing with atmospheric pressure chemical vapor deposition (CVD) process. 3D²G structures produced in various shapes and sizes were characterized using scanning electron microscopy, image analysis, X-Ray Diffraction, micro-CT, 2D Raman spectroscopy, thermogravimetric analysis (TGA), and electrical and electrochemical measurements. By changing the printing design, properties like electrical conductivity, electrochemical behavior, mechanical strength, and structural porosity can be tailored without any requirement for doping or chemical post-processing. The obtained material consists of close to 100% 3D graphene and reveals high thermal stability of up to 500^oC in air. As synthesized, 3D²G can be exposed to mechanical compression which converts it to a shiny thin sheet thus causing a significant increase in its density, electrical conductivity, tensile strength, and Young's modulus. This work brings together two advanced manufacturing approaches, CVD and 3D printing, thus enabling the synthesis of high-quality, binder-free 3D²G structures with a tailored design and properties that appeared to be suitable for multiple applications.