Upcycling Plastic Waste into Valuable Carbon Nanomaterials

Abstract The global issue of plastic waste accumulation is now widely acknowledged as a significant environmental challenge that affects all aspects of life, economies, and natural ecosystems worldwide. Hence, it is crucial to develop sustainable solutions to traditional disposal methods. One promising solution involves upcycling plastic waste into valuable carbon nanomaterials such as carbon nanotubes, graphene, and carbon nanofibers, among others. This critical review provides an overview of the problems associated with plastics, including their various types and properties, as well as their significant impact on the environment and the methods currently employed for waste management. Furthermore, it delves into recent advancements in upcycling plastic waste into carbon nanomaterials through four state‐of‐the‐art methods with the potential for scaling up and enabling industrial applications: thermal decomposition, flash joule heating (FJH), chemical vapor decomposition (CVD), and stepwise conversion. For each method, highly influential and seminal papers were selected, and their research approaches and observed results were thoroughly analysed. This upcycling approach transforms plastic waste into valuable resources, promoting a waste‐to‐value concept that reduces environmental impact and supports the circular economy. By creating new materials from discarded plastics, it addresses waste management challenges while generating economic value.