Nanoarchitectured hollow rod-like hierarchical carbon from Celosia cristata L. vascular bundles for supercapacitors

Abstract

Biomass has become an ideal choice for preparing high-performance carbon materials due to its unique morphological and composition advantages. The vascular bundle system of Celosia cristata L. and rich content of non-metallic elements provide an ideal template for preparing carbon materials with a unique hollow rod-like structure and enhanced electrochemical performance. Using Celosia cristata L. as a precursor, nitrogen and oxygen self-doped carbon materials were successfully prepared through activation process. The effects of activation temperature on the morphology, pore structure, specific surface area, and surface chemical properties of Celosia cristata L.-derived carbon materials were systematically studied. The carbon materials prepared at an appropriate activation temperature exhibited superior microstructure and electrochemical performance, displaying unique vascular bundle morphology and a rich porous structure with abundant oxygen and nitrogen elements. Based on this unique hierarchical pore structure and composition advantage of nitrogen-oxygen co-doping, in a three-electrode system, the specific capacitance of the carbon material was 337 F g⁻¹ (0.5 A g⁻¹), and the capacitance retention rate reached 110% after 50,000 cycles at a current density of 10 A g⁻¹, demonstrating excellent cycling stability. The assembled symmetric supercapacitor achieved a high energy density of 19.5 Wh kg⁻¹. Biomass materials with special intrinsic structures and compositions are of great significance in the development of high-performance energy storage materials and devices.