A facile salt-templating synthesis route of bamboo-derived hierarchical porous carbon for supercapacitor applications

Porous carbon materials have been widely used as electrodes for various energy storage and conversion devices, particularly for supercapacitors. Herein, a bamboo-derived hierarchical porous carbon (BHPC) is directly prepared under air atmosphere via an eco-friendly, one-step, and easily-scalable salt-templating strategy using ZnCl₂/KCl salt mixture as a pore-directing solvent. The obtained BHPC material exhibits large specific surface area (1296 m² g⁻¹) and large total pore volume (1.26 cm³ g⁻¹) which make the BHPC material applicable for supercapacitor as an electrode material. Electrochemical performance evaluated in a 6 M KOH electrolyte in a three-electrode system indicates a high specific capacitance of 394 F g⁻¹ at 1 A g⁻¹ and a good rate capacity with 76.14% capacitance retention at 20 A g⁻¹. The as-prepared symmetric supercapacitor delivers a high energy density of 11 Wh kg⁻¹ at a powder density of 126 W kg⁻¹, and an outstanding lifespan with 81% capacitance retention over 10,000 cycles. These results further open new possibilities for tailoring the surface properties (i.e., heteroatom doping, surface modification, metal oxides incorporation, etc.) towards energy storage and conversion applications such as electrocatalysts for oxygen reduction reaction/hydrogen evolution reaction, lithium-ion batteries, and supercapacitors, as well as wastewater treatment, and electromagnetic wave absorption applications.