Adam Czyżewski

Porous carbon material containing CaO for acidic gas capture: Preparation and properties

A one-step process for the preparation of CaO-containing porous carbons is described. Mixtures of poly(ethylene terephthalate) with natural limestone were pyrolyzed and thus hybrid sorbents could be easily obtained. The polymeric material and the mineral served as a carbon precursor and CaO delivering agent, respectively. We discuss effects of the preparation conditions and the relative amounts of the raw materials used for the preparations on the porosity of the hybrid products. The micropore areas and volumes of the obtained products tended to decrease with increasing CaO contents. Increase in the preparation temperature entailed a decrease in the micropore volume, whereas the mesopore volume increased. The pore creation mechanism is proposed on the basis of thermogravimetric and temperature-programmed desorption measurements. The prepared CaO-containing porous carbons efficiently captured SO2 and CO2 from air. Washing out of CaO from the hybrid materials was confirmed as a suitable method to obtain highly porous carbon materials.

Preparation and properties of porous carbon material containing magnesium oxide

Preparation and properties of porous carbon material containing magnesium oxide Porous carbons loaded with magnesium oxide were prepared through one-step process. Poly(ethylene terephthalate) and natural magnesite were used as carbon source and MgO precursor, respectively. An impact of a temperature and relative amounts of raw components used for preparations on the textural parameters of resulting hybrid materials is presented and discussed. As found, pore structure parameters tend to decrease along with MgO loading and temperature used during preparation process. Micropore area is the parameter being reduced primarily.

Preliminary studies of photocatalytic activity of gypsum plasters containing TiO2 co-modified with nitrogen and carbon

Abstract The conducted studies were focused on the development of the gypsum material exhibiting self-cleaning properties. To this end, the raw gypsum was mixed with unique TiO2-based photocatalysts, previously modified by nitrogen and/ or carbon doping. The photocatalytic activity of the obtained gypsum plasters was evaluated trough the degradation of model organic compound (Reactive Red 198) under UV-vis irradiation. The impact of the photocatalysts presence on the physicochemical properties of the obtained gypsum plasters was evaluated. Furthermore, the role of non-metals presence on the photocatalytic properties of the TiO2 was determined. It was confirmed that the addition of N,C co-modified titanium dioxide into gypsum bestows this material with self-cleaning properties. The highest dye removal rate was displayed by the gypsum plaster containing optimal amount (10 wt%) of co-modified TiO2/N,C photocatalyst, after 20 hours of UV-vis irradiation.

NOx photocatalytic degradation on gypsum plates modified by TiO2-N,C photocatalysts

Abstract In presented studies the photocatalytic decomposition of NOx on gypsum plates modified by TiO2-N,Cphotocatalysts were presented. The gypsum plates were obtained by addition of 10 or 20 wt.% of different types of titanium dioxide, such as: pure TiO2 and carbon and nitrogen co-modified TiO2 (TiO2-N,C) to gypsum. TiO2-N,C photocatalysts were obtained by heating up the starting TiO2 (Grupa Azoty Zakłady Chemiczne Police S.A) in the atmosphere of ammonia and carbon at the temperature: 100, 300 i 600ºC. Photocatalyst were characterized by FTIR/DRS, UVVis/DR, BET and XRD methods. Moreover the compressive strength tests of modified gypsum were also done. Photocatalytic activity of gypsum plates was done during NOx decomposition. The highest photocatalytic activity has gypsum with 20 wt.% addition of TiO2-N,C obtained at 300ºC.

Cementitious Plates Containing TiO2-N,C Photocatalysts for NOx Degradation

Abstract Studies of photocatalytic decomposition of NOx on cementitious plates modified by TiO2-N,Cphotocatalysts are presented. The cementitious plates were obtained by addition of 10 or 20 wt. % of different types of titanium dioxide, such as commercial P25, pure TiO2 and carbon and nitrogen modified TiO2 (TiO2-N,C) to cement.TiO2- N,C photocatalysts were obtained by heating up the starting TiO2 (Grupa Azoty Zakłady Chemiczne Police S.A) in the atmosphere of ammonia and carbon at the temperature 100, 300 i 600 °C. Used photocatalyst were characterized by FTIR/DRS, UV-Vis/DR i XRD methods. Surfaces of modified cementitious plates were studied by optical scanning microscope and the contact angle measurements. Photocatalytic activity of tested materials was done during NOx decomposition. The highest photocatalytic activity has cementitious plate with 20wt.% addition of TiO2-N,C obtained at 300°C.