A critical review on vacuum and atmospheric microwave plasma-based graphene synthesis
R. Barry Johnson, Muhammad Adeel Zafar, Sabu Thomas, Mohan V. Jacob
Abstract
• Overview of graphene’s properties, structure, and synthesis techniques. • Detailed analysis of microwave plasma-based graphene synthesis in vacuum conditions. • Examination of atmospheric pressure microwave plasma-based synthesis and its process parameters. • Discussion on the carbon footprint of graphene synthesis and its environmental impact. Nanotechnology has brought about a paradigm shift in material science, opening a wide range of potential applications in daily uses. Graphene is one of the most important nanomaterials that have applications in electronics, optoelectronics, energy storage, health care and aerospace industries due to its unique and remarkable properties. However, the synthesis of graphene since its discovery has encountered numerous struggles and each method has its advantages and shortcomings. Plasma-based synthesis of graphene, utilising various sources such as radiofrequency (RF) plasma, direct current (DC) plasma, and microwave (MW) plasma, stands out as a promising method due to its controllability, flexibility, and scalability. Among these, microwave plasma-based synthesis is gaining rapid popularity. This method, applicable under both vacuum and atmospheric pressure conditions, offers numerous advantages over other techniques, further enhancing its appeal in the field of graphene production. However, a comprehensive assessment of these methods in terms of equipment, process parameters and their effects on graphene production and quality has not been reported. Therefore, this literature presents a clear comparison of these methods along with the future outlook.