One-step production of N–O–P–S co-doped porous carbon from bean worms for supercapacitors with high performance

Abstract

In recent years, multi-heteroatom-doped hierarchical porous carbons (HPCs) derived from natural potential precursors and synthesized in a simple, efficient and environmentally friendly manner have received extensive attention in many critical technology applications. Herein, bean worms (BWs), a pest in bean fields, were innovatively employed as a precursor via a one-step method to prepare N–O–P–S co-doped porous carbon materials. The pore structure and surface elemental composition of carbon can be modified by adjusting KOH dosage, exhibiting a high surface area (S_BET) of 1967.1 m² g⁻¹ together with many surface functional groups. The BW-based electrodes for supercapacitors were shown to have a good capacitance of up to 371.8 F g⁻¹ in 6 M KOH electrolyte at 0.1 A g⁻¹, and good rate properties with 190 F g⁻¹ at a high current density of 10 A g⁻¹. Furthermore, a symmetric supercapacitor based on the optimal carbon material (BWPC_1/3) was also assembled with a wide voltage window of 2.0 V, demonstrating satisfactory energy density (27.5 W h kg⁻¹ at 200 W kg⁻¹) and electrochemical cycling stability (97.1% retention at 10 A g⁻¹ over 10 000 charge/discharge cycles). The facile strategy proposed in this work provides an attractive way to achieve high-efficiency and scalable production of biomass-derived HPCs for energy storage.