Fabricating carbon-based electrode materials via uptake of amino nano-polystyrene into Pistia stratiotes roots for enhancing supercapacitance

Abstract

Nano-polystyrene, as a new type of organic pollutant, has attracted extensive attention. Nano-sized particles in the water environment could be easily absorbed by hydrophytes and accumulate in root and shoot organs, while porous carbon obtained by high-temperature carbonization is employed as the anode material of supercapacitors, which exhibits good electrochemical performance. In this work, a new strategy of Pistia stratiotes absorbable nano-polystyrene as the pore-forming agent is regarded for preparing porous carbon materials. The absorption of polystyrene nano-plastics by plants will change the graphitization degree and promote pore formation in carbon materials during carbonization. The obtained root-derived carbon materials have a hierarchical pore structure, a large specific surface area (845.61 m² g⁻¹), and a high micropore ratio (52.95%). The prepared carbon materials exhibit a specific capacitance of 253.0 F g⁻¹ at 0.5 A g⁻¹ in 6 M KOH; compared with the control group, the specific capacitance increases by nearly 3 times, and the specific capacitance curve is stable. This paper provides a new strategy for the recovery of nano-plastics from aqueous environments by natural aquatic plants and the preparation of high-performance biomass carbon materials.