Transforming polyethylene terephthalate (PET) into carbon-based nanomaterials: Advancing sustainable solutions for green energy and environmental remediation

Polyethylene terephthalate (PET), a widely used polymer in transparent bottles for water, sanitizers, and other liquids, has seen a surge in consumption, particularly during the COVID-19 pandemic. This increase has resulted in a significant rise in PET-based waste, posing serious environmental and waste management challenges. PET waste, with approximately 11 % fixed carbon, low ash, and 30 % oxygen content, presents a promising raw material for the synthesis of activated carbon and other nanoporous carbon materials. However, conventional methods for converting PET into carbonaceous sorbents often yield limited output and face competition from other recycling pathways, rendering large-scale application impractical. This review critically examines both traditional and emerging techniques for activating PET, comparing its suitability and performance with other polymeric wastes, such as scrap tires. The broader context of plastic waste management is discussed, highlighting its non-biodegradable nature, toxic byproduct release, and impact on ecosystems and human health. Innovative approaches such as recycling and upcycling plastic into carbon-based nanomaterials (CBMs)—including carbon quantum dots, nanoparticles, nanotubes, graphene, and 3D porous carbons—are explored as sustainable alternatives. These plastic waste-derived carbon materials (PWCMs) offer high-value applications in clean energy storage, environmental remediation, and green technologies. The review also identifies eco-friendly production methods, aiming to bridge the gap between academic research and industrial practices. In addressing global energy demands and environmental degradation, PWCMs are positioned as key players in the transition to a circular economy and the development of renewable energy solutions. By consolidating recent advancements and outlining future research directions, this study underscores the potential of PET and other plastic wastes to serve as sustainable feedstocks for high-performance materials, encouraging innovative recycling strategies and contributing to the global effort against plastic pollution. (a) Destructive effects of plastic waste on human health and environment, (b) Schematic illustration for translating plastic waste into carbon-based nanomaterials. • 80 % of plastic waste is underutilized, presenting opportunities for catalytic transformation. • Plastic waste-derived carbon materials (PWCMs) enable green energy and sustainability. • PWCMs show potential in energy storage, production, and eco-friendly environmental uses. • Advances in PET plastics repurpose them into nanomaterials for diverse applications.