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1
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Water purification using a novel reactor with the photoactive refill

100%
Grzechulska-Damszel J., Morawski A.
Polish Journal of Chemical Technology
|
2009
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vol. 11
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issue 1
61-63
EN
The aim of the presented work was the removal of organic dye, Acid Red 18, from water using a novel reactor with the photoactive refill. Titanium dioxide was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The prepared coating exhibits high stability in repeated cycles of water treatment. The complete removal of colour was achieved in a relatively short time of 14 hours. The proposed reactor with the photoactive refill solves the problem of the necessity of the replacement of the reactor or parts of the reactor when the photocatalysts activity decreases. In the case of activity drop of the photocatalyst, only the photoactivve refill can be easily replaced.
2
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Removal of organic dye in the hybrid photocatalysis/membrane processes system

100%
Grzechulska-Damszel J., Morawski A.
Polish Journal of Chemical Technology
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2007
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vol. 9
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issue 2
94-98
EN
The removal of azo dye Acid Red 18 in hybrid photocatalysis/membrane processes systems was investigated. The photocatalytic reactions were conducted in the reactor with photocatalyst suspended in the solution. The reaction solution was recirculated through the ultrafiltration system. A commercially available titanium dioxide (Aeroxide® P25, Degussa, Germany) was used as a photocatalyst. The solution after the photocatalytic/UF reaction was applied as the feed for the membrane distillation process. The changes of various parameters, including the concentration of the dye, pH and the conductivity of the solution, TOC and TDS content were analyzed during the process.It was found that azo dye Acid Red 18 could be successfully decolourised in the hybrid photocatalysis/UF system. The catalyst particles were retained in the feed solution by means of the ultrafiltration membrane so the obtained permeate was free of TiO2. The application of ultrafiltration together with the photocatalytic process results in the separation of photocatalyst from the treated solution but does not give the complete removal of organic matter from the reaction mixture. Membrane distillation applied with the permeate after the photocatalysis/UF process as a feed gives a complete separation of TOC from the treated solution and the obtained product is practically pure water.
3
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Dye decomposition on P25 with enhanced adsorptivity

81%
Janus M., Wawrzyniak B., Tryba B., Morawski A.
Polish Journal of Chemical Technology
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2008
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vol. 10
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issue 2
11-16
EN
The preparation method and the activity of the TiO2-P25/N doped photocatalyst based on commercial titanium dioxide (TiO2 Aeroxide® P-25 Degussa, Germany) are presented. For the TiO2-P25/N preparation TiO2-P25 and gaseous ammonia were kept in a pressure reactor (10 bars) for 4 hours at the temperature of 200°C. This modification process changed the chemical structure of the TiO2 surface. The formation of NH4+ groups was confirmed by the FTIR measurements. Two bands in the range of ca. 1430 - 1440 cm-1 attributed to bending vibrations of NH4+ could be observed on the FTIR spectra of the catalysts modified with ammonia and the band attributed to the hydroxyl groups at 3300 - 3500 cm-1, which were not reduced after N-doping. The photocatalytic activity of the photocatalysts was checked through the decomposition of two dyes under visible light irradiation. The modified TiO2 thus prepared samples were more active than TiO2-P25 for the decomposition of dyes under visible light irradiation.
4
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A preliminary study on antifungal effect of TiO2-based paints in natural indoor light

81%
Markowska-Szczupak A., Ulfig K., Grzmil B., Morawski A.
Polish Journal of Chemical Technology
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2010
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vol. 12
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issue 4
53-57
EN
The antifungal activity of four commercial photocatalytic paints (KEIM Ecosil ME, Titanium FA, Photo Silicate and Silicate D) in natural indoor light was investigated. The paints contained TiO2 in rutile and anatase crystalline forms as evidenced by means of the X-ray diffraction analysis. In most cases the paints inhibited growth of fungi viz. Trichoderma viride, Aspergillus niger, Coonemeria crustacea, Eurotium herbariorum, and Dactylomyces sp. The KEIM Ecosil ME paint displayed the highest antifungal effect in the light, which could be explained with the highest anatase content. The paint antifungal activity and the fungal sensitivity to the TiO2-mediated photocatalytic reaction both decreased in the following orders: KEIM Ecosil ME > Titanium FA > Photo Silicate > Silicate D and T. viride > Dactylomyces sp. > A. niger > E. herbariorum.
5
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Preparation of the TiO2photocatalyst using pressurized ammonia

81%
Wawrzyniak B., Janus M., Grzmil B., Morawski A.
Polish Journal of Chemical Technology
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2007
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vol. 9
|
issue 1
51-56
EN
The industrial hydrated amorphous titanium dioxide (TiO2ċ xH2O) was modified by treatment inside a chemical reactor under elevated pressure at low temperatures for 4 hours in an ammonia atmosphere. On the basis of the FTIR/DRS analysis the presence of nitrogen was confirmed. The XRD patterns of all of the catalysts exhibit mainly the diffraction lines of anatase phases. The photocatalytic activity of the modified photocatalysts was determined and compared to TiO2-P25 (Degussa, Germany). The high rate of phenol and dye degradation was obtained for the catalysts modified at 180°/15atm. TiO2-P25 showed similar activity in phenol decomposition like TiO2-15bar, whereas it was more active in dye decomposition.
6
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Photocatalytic mineralisation of humic acids using TiO2modified by tungsten dioxide/ hydrogen peroxide

71%
Tryba B., Piszcz M., Borowiak-Paleń E., Grzmil B., Morawski A.
Polish Journal of Chemical Technology
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2012
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vol. 14
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issue 2
54-61
EN
TiO2 of anatase structure was modified by tungsten dioxide and H2O2 in order to obtain WO3-TiO2 photocatalyst with enhanced photocatalytic activity under both, UV and artificial solar light irradiations. WO2 was dissolved in 30% H2O2 and mixed with TiO2 in a vacuum evaporator at 70°C. Such modified TiO2 was dried and then calcinated at 400 and 600°C.The prepared samples and unmodified TiO2 were used for the photocatalytic decomposition of humic acids (Leonardite standard IHSS) in the aqueous solution under irradiations of both, UV and artificial solar light. Modification of TiO2 with tungsten dioxide and H2O2 improved separation of free carriers in TiO2 which resulted in the increase of OH radicals formation. Calcination caused an increase of anatase crystals and higher yield in OH radicals. The uncalcined samples showed high abilities for the adsorption of HA. Combination of adsorption abilities and photocatalytic activity of photocatalyst caused that the uncalcined TiO2 modified with WO2/H2O2 showed the shortest time of HA mineralisation. The mineralisation of HA under the artificial solar light was much lower than under the UV. It was proved that, although OH radicals are powerful in the decomposition of HA, adsorption can facilitate the contact of the adsorbed molecules with the photocatalyst surface and accelerate their photocatalytic decomposition.
7
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TiO2modified by ammonia as a long lifetime photocatalyst for dyes decomposition

71%
Choina J., Dolat D., Kusiak E., Janus M., Morawski A.
Polish Journal of Chemical Technology
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2009
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vol. 11
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issue 4
1-6
EN
Ammonia-modified TiO2 (TiO2/N), prepared in a pressure reactor was used as the well- active and longlife photocatalyst for the azo dye (Reactive Red 198) decomposition. The effect of aeration and the different value of the pH of the reaction medium on the photocatalytic degradation of Reactive Red 198 in water has been investigated. It has been reported that the degradation is greatly influenced by the reaction pH and the faster decomposition of azo dye took place at pH 3.5. When the solution was acidic, a larger amount of azo dye on the positively charged surface of TiO2 photocatalysts was adsorbed. From the obtained results it can be seen that the effectiveness of the decolourisation of the solution was faster by using the nitrogen-modified TiO2.
8
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Photocatalytic properties of nanocrystalline TiO2 thin films doped with Tb

62%
Wojcieszak D., Kaczmarek D., Domaradzki J., Prociow E., Morawski A., Janus M.
Open Physics
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2011
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vol. 9
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issue 2
354-359
EN
In this work photocatalytic properties of TiO2 thin films doped with different amount of Tb have been described. Thin films were prepared by high energy reactive magnetron sputtering process. Comparable photocatalytic activity has been found for all doped TiO2 thin films, while different amounts of Tb dopant (0.4 and 2.6 at. %) results in either an anatase or rutile structure. It was found that the terbium dopant incorporated into TiO2 was also responsible for the amount of hydroxyl groups and water particles adsorbed on the thin film surfaces and thus photocatalytic activity was few times higher in comparison with results collected for undoped TiO2 thin films.
9
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Carbon modified TiO2photocatalysts for water purification

62%
Morawski A., Janus M., Tryba B., Toyoda M., Tsumura T., Inagaki M.
|
EN
Carbon can form different structures with TiO2: carbon-doped TiO2, carbon coated TiO2 and composites of TiO2 and carbon. The presence of carbon layer on the surface of TiO2 as well as the presence of porous carbon in the composites with TiO2 can increase the concentration of organic pollutants on the surface of TiO2, facilitating the contact of the reactive species with the organic molecules. Carbon-doped TiO2 can extend the absorption of the light to the visible region by the narrowing of the band gap and makes the photocatalysts active under visible light irradiation. TiO2 loaded carbon can also work as a photocatalyst, on which the molecules are adsorbed in the pores of carbon and then they undergo the photocatalytic decomposition with UV irradiation. Enhanced photocatalytic activity for the destruction of some organic compounds in water was noticed on the carbon coated TiO2 and TiO2 loaded activated carbon, mostly because of the adsorptive role of carbon. However, in carbon-doped TiO2, the role of carbon is somewhat different, the replacement of carbon atom with Ti or oxygen and formation of oxygen vacancies are responsible for extending its photocatalytic activity towards the visible range.
10
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Magnetic resonance study of annealed and rinsed N-doped TiO2 nanoparticles

52%
Guskos N., Typek J., Guskos A., Zolnierkiewicz G., Berczynski P., Dolat D., Grzmil B., Morawski A.
Open Chemistry
|
2013
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vol. 11
|
issue 12
1996-2004
EN
Nanoparticles of nitrogen-modified TiO2 (N-doped TiO2) calcined at 300°C and 350°C, have been prepared with and without water rinsing. Samples were characterized by x-ray diffractrometry (XRD) and optical spectroscopy. The electron paramagnetic resonance (EPR) spectra from centers involving oxygen vacancies were recorded for all samples. These could be attributed to paramagnetic surface centers of the hole type, for example to paramagnetic oxygen radicals O−, O2−etc. The concentration of these centers increased after water rising and it further increased for samples annealed at higher temperature. Additionally, for samples calcined at 300°C, and calcined at 350°C and rinsed, the EPR spectra evidenced the presence of magnetic clusters of Ti3+ ions. The photocatalytic activity of samples was studied towards phenol decomposition under unltraviolet-visible (UV-Vis) irradiation. It was found that, in comparison to the starting materials, the rinsed materials showed increased photocatalytic activity towards phenol oxidation. The light absorption (UV-Vis/DRS) as well as surface Fourier transform infrared/diffuse reflectance spectroscopy (FTIR/DR) studies confirmed a significantly enhanced light absorption and the presence of nitrogen groups on the photocatalysts surfaces, respectively. A significant increase of concentration of paramagnetic centers connected with oxygen vacancies after water rising has had an essential influence on increasing their photocatalytic activity. [...]
11
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Selenium as marker for cancer risk and prevention

33%
Lener M., Jaworska K., Muszyńska M., Sukiennicki G., Durda K., Gupta S., Złowocka-Perłowska E., Kładny J., Wiechowska-Kozłowska A., Grodzki T., Jaworowska E., Lubiński J., Górecka-Szyld B., Wilk G., Sulikowski M., Huzarski T., Byrski T., Cybulski C., Gronwald J., Dębniak T., Ashuryk O., Tołoczko-Grabarek A., Jakubowska A., Morawski A., Lubiński J.
Polish Journal of Surgery
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2012
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vol. 84
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issue 9
470-475
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