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

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 Fe<inf>3</inf>O<inf>4</inf> (WrGOs-Fe<inf>3</inf>O<inf>4</inf>) can be used to remove drugs from water treatment plants and for energy storage applications specifically supercapacitors. WrGOs and WrGOs-Fe<inf>3</inf>O<inf>4</inf> showed the removal efficacy of diclofenac and caffeine drugs from water samples with Q<inf>max</inf> 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, WrGOs-Fe<inf>3</inf>O<inf>4</inf> was first examined in a three-electrode setup using 1 M H<inf>2</inf>SO<inf>4</inf> as an electrolyte along with the WrGOs. The composite WrGOs-Fe<inf>3</inf>O<inf>4</inf> demonstrated a good specific capacitance of 488F/g at 1 A/g current density. For practical application, a Supercapacitor (SC) device was fabricated using WrGOs-Fe<inf>3</inf>O<inf>4</inf> 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 1 M H<inf>2</inf>SO<inf>4</inf> 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?