Polymer carbon dots from plastics waste upcycling

Abstract

We present the upcycling of plastic waste into photoluminescence polymer carbon dots (C-Dots). The recycling was conducted to the polypropylene (PP) plastic waste using a simple heating process at around its melting point temperatures of 200 °C, 250 °C, and 300 °C. The optical properties and size as well as structure of polymer C-Dots from PP plastic waste are successfully identified. The newly polymer C-Dots from plastic waste recycling have absorption spectra at the 400–435 nm wavelength range. We obtained a very unique rare phenomenon on the emission spectra that it happened two peaks emission wavelengths of 410 nm (3.03 eV) and 440 (2.83 eV). Polymer C-Dots from PP plastic waste has an average particles size of ∼15 nm (200 °C), ∼11 nm (250 °C) and ∼8 nm (300 °C). The alteration of the optical properties—absorption spectra and emission spectra—as well as particle size of polymer C-Dots are caused by structural change of PP plastic waste due to heating process in recycling process. During the heating process on PP plastic waste, the carbon chain binds oxygen from the environment and forms C=O carbonyl group on the wave number 1638 cm-1 which is the main constituent of Polymer C-Dots. Recycling of PP plastic waste into polymer C-Dots has a huge potential to be used as materials for photocatalyst, bioimaging as well as sensors in optoelectronic materials. Furthermore, the result of this study has a role as real action in term of environmental conservation and it answers how to overcoming the problem of plastic waste.