Strategies for scalable gas-phase preparation of free-standing graphene

Abstract

The preparation of graphene with high quality serves as a prerequisite for its usage. Traditional methods of graphene production, represented by liquid-phase exfoliation and chemical vapor deposition, either sacrifice the quality and purity of graphene or are limited by the substrate and catalyst. Developing simple and scalable preparation methods of high-quality and high-purity graphene remains a big challenge. Herein, we have reviewed the gas-phase methods including carbonization, combustion, arc discharge, and atmospheric plasma for scalable preparation of free-standing graphene, which are catalyst-, substrate-, solvent-free, and without the need for complex post-treatment methods. The obtained graphene exhibits characteristics of high quality and high purity. Moreover, applications of free-standing graphene were also summarized. Finally, perspectives on opportunities and challenges of free-standing graphene have been discussed.