Preparation and application performance study of biomass-based carbon materials with various morphologies by a hydrothermal/soft template method

Nitrogen-doped carbon materials with controllable morphologies were prepared via a soft template method using chitosan as the carbon and nitrogen source and F127 or ionic liquid as the template. The performance of the materials as electrodes and adsorbents for carbon dioxide removal were evaluated. Carbon spheres (CSs) with developed micropore structures were obtained without a template, whereas a tubular structure (CSF) containing mesopores with long-range order was obtained using F127. Layered carbon (CSI) containing micro-/mesopores with short- and long-range order was obtained using an ionic liquid. The samples exhibited graphite-like structure and the soft template increased the graphitization degree. Nitrogen existed mainly in the form of pyridine and pyridone groups in CSs and CSF and as pyridine, pyridone, and quaternary groups in CSI. The specific capacitances of CSs, CSF, and CSI were 144, 161, and 178 F g-1, respectively, at a current density of 1.0 A g-1 in 1 M sulfuric acid. The carbon dioxide adsorption capacities of CSs, CSF, and CSI were 142, 73, and 115 mg g-1, respectively; CSs displayed the highest value because of its developed micro- and ultramicroporous structure. Our results indicated that these carbon materials with various morphologies can be used as both electrodes and adsorbents.