Surface chemistry of pyrolyzed starch carbons on adsorption of ammonia and carbon disulfide

Amylose and amylopectin were pyrolyzed at 400 °C and then oxidized with HNO3 and H2SO4 to modify its surface chemical properties. The pore structures and surface chemical properties of pyrolyzed carbons before and after oxidation were characterized and compared by nitrogen adsorption isotherms, thermogravimetric analysis, FT-IR spectra and SEM images. The results indicated that pore structures were hardly changed after oxidation, but the lactonic and phenolic groups could be markedly increased after oxidation, and the adsorption capacities for ammonia and carbon sulfide were enhanced.