Sustainable Conversion of Mixed Plastics into Porous Carbon Nanosheets with High Performances in Uptake of Carbon Dioxide and Storage of Hydrogen

Conversion of waste plastics into high value-added carbon nanomaterials has gained wide research interest due to the requirement of sustainable development and the ever-increasing generation of waste plastics. However, most of studies are limited to single component plastic; besides, little attention has been paid to carbon nanosheets (CNS). Herein, CNS were prepared by catalytic carbonization of mixed plastics consisting of polypropylene, polyethylene, polystyrene, poly(ethylene terephthalate), and polyvinyl chloride on organically modified montmorillonite. After KOH activation, porous CNS (PCNS) were produced. The morphology, microstructure, phase structure, textural property, surface element composition, and thermal stability of PCNS were investigated. PCNS contained randomly oriented lattice fringes and showed a layered morphology consisting of thin, leaf-like, agglomerated nanosheets ranging from hundreds of nanometers to several micrometers in length. Besides, PCNS exhibited high specific surface area (1734 m2/g) and large pore volume (2.441 cm3/g). More importantly, PCNS displayed high performances in the uptake of carbon dioxide and storage of hydrogen. It is believed that this work not only paves the way for utilization of mixed waste plastics but also provides a facile sustainable approach for the large-scale production of valuable PCNS for energy storage and environmental remediation.