Biomass-Based Nitrogen-Doped Hollow Carbon Nanospheres Derived Directly from Glucose and Glucosamine: Structural Evolution and Supercapacitor Properties

Carbon-based materials generated from biomass have been studied extensively. However, to the best of our knowledge, there is no report of any hollow structured carbon nanospheres directly derived from biomass without the use of templates. In this research, a green route to directly convert biomass to nitrogen-doped hollow carbon nanospheres (N-HCSs) was reported, where only glucose and glucosamine were used as the precursors and an aerosol-assisted process was employed. In the process, amino groups of glucosamine triggered the coassembly between glucose and glucosamine, resulting in the structural evolution of hollow structures. The aerosol-based technology ensures the obtained particles have a spherical morphology and are in the nanoscale size range. The as-prepared materials have been thoroughly characterized by SEM, TEM, HAADF-STEM, EELS mapping, XPS, XRD, Raman, and nitrogen adsorption. Owing to the unique structural and surface properties, the resultant N-HCSs exhibited excellent electrochemical properties for energy storage, including a high specific capacitance of 266 F g(-1) at 0.2 A g(-1), long cycling stability with 96.8% of capacitance retained after 3000 cycles, and a fast charge discharge process. This discovery could be adapted to guide the design and synthesis of a variety of hollow materials from biomass for wider applications in the environment and energy fields.