Transformative and sustainable approach to waste plastic mixture valorization

The development of innovative methods for waste plastic valorization can benefit the environment and economy. In this study, the full spectrum of products (gas, oil, and solid products) resulting from the pyrolysis-reforming of a plastic mixture functioned as precursors of value-added products: 1) ethylene-propylene copolymers, 2) polyacrylonitrile (PAN)-based carbon nanofibers (CNFs), and 3) carbon quantum dots (CQDs). The CNFs were subsequently applied as supercapacitor electrodes, whereas the CQDs acted as co-sensitizers for the primary sensitizer, N3, in dye-sensitized solar cells (DSSCs). Adding oil to PAN increased the specific capacitance of the CNFs by 46.12% to 226.64F/g, compared with that of pure PAN CNFs. With the aid of CQDs, the short-circuit current density and photo-conversion efficiency of DSSCs increased by 25.89% and 17.08%, respectively. Mechanisms associated with the integrated valorization pathway were proposed.