Promoting discarded packing waste into value-added 2D porous carbon flakes for multifunctional applications

In this work, a prolific reuse of waste foam peanuts into eco-benign and cost-effective two-dimensional (2D) activated carbon nanoflakes (CFs) was presented for use in CO2 capture and supercapacitor applications. The 2D nanoporous carbon sheets-like structures were derived by a two step process including simple carbonization followed by KOH activation (C:KOH = 1:1). With the varied activation temperature, the surface area and porosity have been controlled, which demonstrate the narrow pore size distribution in the range of <1 nm and mesopore in the range of ∼40 nm. Among the samples derived, CF-800 shows excellent CO2 sorption capacity corresponding to 3.3–3.45 mmol/g with the highest surface area corresponding to 1041 m2/g and outstanding cyclic stability over 21 cycles. Meanwhile, the prepared 2D activated CFs demonstrated superior energy storage properties including high specific capacitance of 250 F/g at 1 A/g with exceptional cyclic stability. Moreover, the symmetric supercapacitor has been fabricate...