Upcycling Waste Polyethylene into Carbon Nanomaterial via a Carbon-Grown-on-Carbon Strategy

Upcycling waste plastics (e.g., polyethylene (PE)) into value-added carbon products is regarded as a promising approach to address the increasingly serious waste plastic pollution and simultaneously achieve carbon neutrality. However, developing new carbonization technology routes to promote the oxidation of PE at low temperature and construct the stable cross-linking network remains challenging. Here, a facile carbon-grown-on-carbon strategy is proposed using carbon black (CB) to convert waste PE into core/shell carbon nanoparticles (CN) in high yields at low temperature. The yield of CN remarkably rises when the heating temperature decreases or the dosage of CB grows. The obtained CN displays turbostratic structure and closely aggregated granular morphology with a size of approximate to 80 nm. It is found, prior to the oxidation and carbonization of PE, CB forms a 3D network architecture in the PE matrix. More importantly, CB not only catalyzes the partial oxidation of PE to form PE macromolecular radicals and introduce oxygen-containing groups at low temperature in the early stage, but also favors for the construction of a stable cross-linking network in the latter stage. This work offers a facile sustainable strategy for chemical upcycling of PE into value-added carbon products without post-treatments or usage of metallic catalysts.

Automated summary

This study proposes a facile and sustainable strategy to convert waste polyethylene into core/shell carbon nanoparticles using carbon black. It is found that carbon black plays a crucial role in catalyzing the oxidation of polyethylene and constructing a stable cross-linking network at low temperature.