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 nitrogendoped 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.