Mesoporous nitrogen-doped carbon from nanocrystalline chitin assemblies

Nanocrystalline chitin has been used both as a soft template and as the carbon and nitrogen sources for preparing mesoporous nitrogen-doped carbon materials with a layered structure. The chitin nanorods prepared by sequential deacetylation and hydrolysis of fibrils isolated from king crab shells organized into a nematic liquid-crystalline phase. Silica/chitin composites obtained by sol-gel condensation of silica in the presence of liquid-crystalline chitin were carbonized and etched to yield mesoporous nitrogen-doped carbon films that replicate the layered nematic organization of the nanocrystalline chitin films. The high degree of mesoporosity and nitrogen doping in the liquid-crystalline biopolymer-derived carbon replicas allows them to function as efficient supercapacitor electrode materials. Films embedded with tin oxide nanoparticles displayed superior performance for supercapacitor electrodes.