title: Determination of the Surface Oxidation Degree of the Carbonaceous Materials by Quantitative TG-MS Analysis.
abstract: The developed quantitative TG-MS analysis was used for the determination of the surface oxidation degree of activated carbon cryogels. The surface chemistry of a prepared carbon cryogels pyrolyzed at 400 and 500 °C was modified using H3PO4, Fenton-like reaction, (NH4)2S2O8with H2SO4and HNO3with H2O2into a different surface oxidation degree. The influence of activation method and the amount of oxygen surface groups were characterized by elemental analysis, immersion calorimetry, water vapor adsorption, and Boehm titration. The obtained results from these methods were compared with the amount of surface oxygen determined by TG-MS. It was found out, that with the more intensive oxidation method (Fenton < (NH4)2S2O8with H2SO4< HNO3with H2O2) the concentration of oxygen-containing surface groups increases, which lead to considerably higher parameters of immersion heat, amount of adsorbed water and acidity of the sample surface. The H3PO4treatment of carbon cryogels causes no significant changes in the surface chemistry. The results obtained from the TG-MS analysis imply the good agreement with the results obtained from other used methods. It was proved that the quantitative TG-MS analysis could be a useful tool for the characterization of the surface of the carbonaceous materials.
authors.affiliation: University of Ostrava , Faculty of Science, Institute of Environmental Technologies, Department of Chemistry, 30. dubna 22, 701 03 Ostrava, Czech Republic.
authors.forename: Gabriela
authors.identifier: 0000-0002-7664-8802
authors.initials: G
authors.lastname: Hotová
authors.affiliation: University of Ostrava , Faculty of Science, Institute of Environmental Technologies, Department of Chemistry, 30. dubna 22, 701 03 Ostrava, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Slovák