A review of commercial plastic waste recycling into graphene materials

Since their discovery and application in human life, plastic has become the most popular materials on the planet, with applications in almost all fields. The fast growth of the world population and the remarkable expansion of the worldwide economy, along with increased global productivity, are the primary causes of the overproduction of plastic materials. Plastic waste poses a growing hazard to human life by contaminating the environment, particularly water and soil, which in turn leads to serious diseases and endangers human life. Thus, while discussing waste recycling in general, the topic of plastic waste recycling is always given priority. To maximize recycling, various ideas and discussions have been put forth over the years for turning plastic waste into other materials, such as carbonaceous materials, particularly graphene. Some top-down methods such as pyrolysis and flash Joule heating provide high conversion efficiencies of up to 70% and 90%, respectively, but require large energy supplies to reach extremely high temperatures from 600 °C to 3000 °C. In contrast, typical bottom-up methods such as chemical vapor deposition and microwave plasma provide remarkable efficiencies of up to 50% under specific conditions of inert gas environments. Thus, this review introduces some of the groundbreaking methods reported to date for recycling plastic waste into one of the materials of the century-graphene.