Functional carbon materials from waste plastics: synthesis and applications

The global accumulation of waste plastics has led to severe environmental pollution, posing a serious threat to ecosystems. Conventional disposal methods, such as landfilling, mechanical recycling, and incineration, remain limited by low conversion efficiency, modest economic benefits, and the risk of secondary pollution. Converting plastics into high-value functional carbon materials offers a promising strategy for waste plastic recovery. This review systematically summarizes the physicochemical properties of major plastics, including polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene. It then discusses representative functional carbon materials—such as carbon nanotubes, graphene, porous carbon, carbon spheres, carbon nanosheets, carbon quantum dots, and soft carbon—derived from waste plastics using both conventional processes (direct pyrolysis, catalytic pyrolysis, one-pot synthesis, and templating methods), and emerging technologies (flash Joule heating and microwave-assisted pyrolysis). Furthermore, the applications of these functional carbon materials in environmental remediation (e.g., CO2 adsorption, antibiotic removal, electromagnetic wave absorption, and heavy metal ion adsorption), and energy storage (e.g., lithium-ion batteries and supercapacitors) are reviewed. This work provides a timely overview of recent advances in the field and highlights pathways toward the sustainable utilization of waste plastics.