Recycling and repurposing of waste carbon nanofiber polymers: a critical review

Carbon nanofibers are a class of lightweight, high-performance composite materials. Their bespoke porous defects, intricate multiporous channel topography, and substantial specific surface area render them instrumental in addressing many pivotal challenges within the environmental and energy sectors. Despite the escalating research dedicated to the applications of nanofibers across diverse fields, scant attention has been accorded to the disposal of waste fibers. The paradigms for the recovery and subsequent reutilization of these high-caliber carbon nanofibers remain unformulated, culminating in substantial wastage and concomitant environmental degradation annually. This study highlights the urgency of recycling these fibers, summarizing the importance of recycling, relevant policies, and current methodologies while critiquing the field's status quo. Traditional recovery techniques are insufficient for these premium nanofibers, necessitating innovative, efficient recycling strategies. Emphasizing the necessity for original recycling technologies, we advocate for conceptualizing degradable fibers driven by reversible chemical bonds, transitioning towards biomass-derived nanofibers, and a fundamental reorientation to perceive waste as a valuable asset. Future strategies should focus on enhancing recovery rates and maintaining fiber functional structure, with policy support and increased environmental awareness crucial for advancement. Our insights aim to guide further studies towards efficient and sustainable solutions for carbon nanofiber management.