Multiwall carbon nanotubes derived from plastic packaging waste as a high-performance electrode material for supercapacitors

Abstract

The increasing plastic pollution and dwindling supply of fossil fuels have ignited research on the use of waste for generation of renewable energy and its reliable storage systems. This study investigates the feasibility of developing multiwall carbon nanotubes (MWCNTs) from flexible plastic packaging, as a prospective electrode material for the application in supercapacitors. The MWCNTs derived from flexible plastic packaging waste are functionalized using nitric acid to introduce oxygenated functional groups at their surfaces. Then, the MWCNTs are utilized as electrode material in supercapacitors, and their performance is compared with commercial MWCNTs. The results indicate that the as-prepared MWCNTs exhibit superior capacitive performance as compared to commercial MWCNTs. Moreover, the functionalized MWCNTs demonstrate an improved capacitive performance among all the samples and display a double capacitance value as compared to commercial MWCNTs which is attributed to their higher electrochemical activity and faster charge transfer. These findings suggest that MWCNTs synthesized from flexible plastic packaging waste can be a superior alternate to the commercial MWCNTs. If developed at commercial scale, this will create a double-win situation where plastic waste is reduced and cost-effective high-performance electrodes are developed for energy storage applications.