A microporous and high surface area active carbon obtained by the heat-treatment of chitosan

A method is described for converting chitosan into a high surface area and porous active carbon using a Na2CO3 solution impregnated into a partly depolymerized, protonated and water soaked chitosan. The wet chitosan paste is heat treated and transformed into a nonporous solid i.e. a carbon-rich matrix with uniformly suspended Na2CO3 nanocrystallites. Subsequent HCl etching opens cavities in the matrix due to the removal of the Na2CO3. The active carbon is high surface area (above 400 m2/g), microporous (below 1 nm) and nitrogen-rich (above 6% atomic).