Recent developments in the synthesis of graphene and graphene-like structures from waste sources by recycling and upcycling technologies: a review

Among carbon-based nanomaterials, graphene and its derivatives have received remarkable attention due to their unique thermal, mechanical, and electronic properties and two-dimensional structure. The unique combination of graphene’s characteristics with the selected matrix exhibits extraordinary synergies in various fields such as energy, automotive, aerospace, and electronics. However, there are serious bottlenecks for the industrialization of graphene and increasing the number of graphene-based products in mass scale owing to high cost, harsh and toxic reaction conditions, agglomeration of nanosheets and limited production capacity. Therefore, the new trends focus on the usage of waste sources to produce value-added products in order to contribute waste management and circular economy. This review summarizes underlying and emerging trends for the development of recycling and upcycling methods for cost-efficient and mild synthesis of graphene and its derivatives from waste sources such as plastics, agricultural biomass waste, and cellulosic waste. The state of the research activities provides better understanding in the fabrication of graphene-like materials from waste products as solid carbon sources by using top-down and bottom-up approaches