Sugarcane Bagasse-Derived Activated Carbon as a Potential Material for Lead Ions Removal from Aqueous Solution and Supercapacitor Energy Storage Application

Abstract

Sugarcane bagasse-based activated carbon (AC) was produced via a physical activation method using CO2, to remove lead (Pb) ions from an aqueous solution. The physical and chemical properties of ACs were examined by scanning electron micrograph (SEM), Brunauer–Emmett–Teller (BET) surface area, and Fourier-transform infrared spectroscopy (FTIR) analysis. The effect of both pH and contact time on adsorption was studied via a batch process. Based on the BET results, we have identified that BET surface area and micropore volume decreased at the highest activation temperature, while the intensity of the functional groups increased when the activation temperature was raised. The adsorption isotherms were best fitted with the Langmuir equation, which was used to describe the adsorption process and to examine the adsorption mechanisms of Pb(II) on the AC. The maximum adsorption capacity of Pb(II) was 60.24 mg g−1 with AC850. The adsorption kinetic study closely followed the pseudo-second order (R2 > 0.99). AC has the potential to economically remove metal ions in the purification process of wastewater. AC850 was also utilized in the manufacture and testing of pouch cell supercapacitors to demonstrate the potential of the sugarcane bagasse family of materials in energy storage applications. The devices made with the unmodified, nonoptimized material used for Pb(II) sorption demonstrated high rate and power-energy characteristics (>50% capacitance retention with 10-fold increase in current density, 10 Wh Kg−1 at 2500 W Kg−1, active material mass) but there remains a need for further optimization, particularly the removal of oxygen functionality, to enhance lifetime and specific capacitance. This work demonstrated the potential for sugarcane bagasse carbons across environmental applications.