Transformative and sustainable approach to waste plastic mixture valorization

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.499, p.156558, Article 156558
• Main Authors: Chen, Zhe, Lu, Wenyang, Paneru, Ramhari, Yang, Qian, Gong, Weibo, Tie Tjeng, So, Goroncy, Alexander, Dai, Qilin, Zhang, Jinwen, Kammen, Daniel M., Wang, Tongtong, Fan, Maohong
• Format: Article
• Language: English
• Subjects: Carbon nanofibers; Carbon quantum dots; Dye-sensitized solar cell; Ethylene–propylene copolymer; Supercapacitor; Waste plastic valorization
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156558

Schematic of the proposed integrated method (The cited references are shown in Supplementary information, “3 References of Fig. 1”). This graphical abstract is also the Fig. 1 of the manuscript. [Display omitted] •Plastic-derived gas, oil, and solid were all valorized.•Valorized products were EP copolymer, CNFs, and CQDs.•CNFs were used assupercapacitor electrodes.•The oil increased the specific capacitance of CNFs by 46.12%.•CQDs as co-sensitizer increased the photo-conversion efficiencyof DSSCs by 25.89%. 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, whereasthe 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.