CONVERSION OF SELECTED PLASTIC WASTE INTO CARBON NANOMATERIALS FOR APPLICATION IN THE ADSORPTION OF CARBON DIOXIDE AND ENERGY STORAGE

Abstract

Plastic waste is a major environmental problem. It is non-biodegradable and can take hundreds of years to decompose. Plastic waste can also pollute waterways and oceans, harming wildlife and ecosystems. There are several ways to recycle plastic waste. One promising method is to convert it into carbon-based materials. Carbon-based materials have many potential applications, including energy storage, catalysis, and electronics. This study utilized hydrothermal/ solvo-thermal techniques to convert plastic waste into carbon-based nanomaterial at lower temperatures with zero emissions. The poly(ethylene terephthalate (PET) was converted into PT-NANO, and polyethylene (PE) waste into PE-NANO carbon nanomaterials (CNMs) for energy storage in supercapacitors. Also, the Polystyrene (PS) waste was converted into PS-ACT derived CNMs for carbon dioxide adsorption application The produced carbon-based nanomaterials powder was characterized for physical and chemical properties using different techniques, including BET, TGA-DSC, UV-Vis, FTIR, Raman spectroscopy, XRD, FESEM, TEM, and proton NMR analysis. The characterization confirmed the complete conversion of plastic waste to solid fractions of carbon nanomaterial. The PT-NANO and PE-NANO powders were tested with electrochemical characterization for energy storage because of their physical-chemical properties like specific surface area. The PT-NANO symmetric fabrication showed a specific capacitance of 250.8 F/g, energy density of 34.83 Wh/kg, and power density of 999.9 W/kg with a current density of 0.5A/g. The device fabrication exhibited high cycle stability and high capacitance retention of 96.8% with a current density of 1.5A/g after 10000 cycles. The PE-NANO electrochemical test revealed a specific capacitance of 155.5F/g with an energy density of 21.6W h/kg and a current density of 0.25A/g. Furthermore, after 9000 cycles at a steady current density of 1.0A/g, the materials retained 98.5% of their capacitance. The hydrothermal treatment of polystyrene (PS) in the presence of potassium hydroxide resulted in an efficient carbon sorbent with pores volume of 0.068cm3/g. The sorbent’s CO2 capacity at 25 °C is 3.8 mmol/g at 1 bar and 3.0 mmol/g at 0.1 bar, and it regenerates when the temperature reaches 80 ± 5 °C. As a result, this PS-derived carbon compound exhibited potential to absorb CO2 from high-emissions sources. The conversion of plastic waste into carbon-based materials is a promising method for reducing plastic pollution and creating new value from waste. These methods have the potential to make a significant contribution when converted at large scale as the best sustainable method for waste management.