Waste plastics derived reduced graphene oxide-based nanocomposite with Fe3O4 for water purification and supercapacitor applications

Abstract

Whether plastic waste ends up in a landfill or washed into the ocean, the ecological consequences of plastic pollution remain a constant challenge. In this work, we showcased how plastic waste derived reduced graphene oxide (WrGOs) and its composite with Fe3O4 (WrGOsFe3O4) can be used to remove drugs from water treatment plants and for energy storage applications specifically supercapacitors. WrGOs and WrGOs-Fe3O4 showed the removal efficacy of diclofenac and caffeine drugs from water samples with Qmax 11.06 mg/g and 15.1 mg/g for diclofenac, and 8.77 mg/g and 15.24 mg/g for caffeine. For energy storage purposes, WrGOsFe3O4 was first examined in a three-electrode setup using 1M H2SO4 as an electrolyte along with the WrGOs. The composite WrGOs-Fe3O4 demonstrated a good specific capacitance of 488 F/g at 1 A/g current density. For practical application, a Supercapacitor (SC) device was fabricated using WrGOs-Fe3O4 as electrode material in a two-electrode setup which exhibited excellent energy density (52.57 Wh/Kg at 0.5 A/g), high cyclic stability (90.03 %) and wider potential window of 1.4 V in 1M H2SO4 aqueous electrolyte due to stronger ionic diffusion. Thus, this study begs the question: Can graphene-based composite products derived from waste plastic be exploited for drug removal and supercapacitor applications?