Porous Carbon in Durian Shell Doped with Heteroatoms and Its Electrochemical Properties Research

Using discarded durian shell (DS), a waste biomass, as the raw material, DS-based activated carbon was prepared. Heteroatom doping with thiourea as the nitrogen and sulfur source was then introduced on the precursor of DS activated carbon to investigate its impact on the material’s morphology and electrochemical energy storage performance as a supercapacitor electrode. Characterization techniques such as XPS, XRD, and electrochemical tests were employed to evaluate the relevant properties of the material. The results revealed that when the mass ratio of thiourea to DS activated carbon reached 2:1, the specific surface area of S-DCK-2 peaked at 2394 m²·g⁻¹. Electrochemical testing demonstrated that S-DCK-2 exhibited a remarkable specific capacitance of 370 F·g⁻¹ at 0.5 A·g⁻¹, indicating its superior electrochemical performance. Subsequently, electrodes were assembled into S-DCK-2//S-DCK-2 symmetric supercapacitors in a two-electrode configuration. The results showed that the S-DCK-2//S-DCK-2 device achieved a specific capacitance of 113 F·g⁻¹ in 6 mol·L⁻¹ KOH at a current density of 0.5 A·g⁻¹. The material exhibited an energy density of 15.83 Wh·kg⁻¹ and a power density of 313 W·kg⁻¹. The experiment confirmed that doping with sulfur and nitrogen enhanced the pseudocapacitance capacity, leading to improved electrochemical performance.