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1

Fotokatalizatory i fotoelektrokatalizatory w procesach wytwarzania nadtlenku wodoru

Gańczarczyk Roman M.

Wiadomości Chemiczne

|

2023

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[Z] 77, 11-12

1017--1040

EN

A significant contemporary challenge in the field of science and technology pertains to the development of innovative and sustainable methods for energy acquisition. The dynamic advancement of solar energy conversion techniques has led to the swift commercialization of photovoltaic cell technology, concomitantly creating a demand for cost-effective energy conversion and storage systems. An interesting solution to this challenge lies in the application of photocatalytic and photoelectrocatalytic synthesis to produce energy-rich molecules. One of the possible solutions under consideration in this context is hydrogen peroxide artificial photosynthesis. In recent years, several research efforts have been dedicated to the photo-assisted generation of hydrogen peroxide through oxygen reduction and water oxidation. In this brief review, the fundamental aspects related to photocatalytic and photoelectrocatalytic processes have been presented. Particular attention was paid to issues related to various groups of active photo(electro)catalysts used in the synthesis of hydrogen peroxide, and the latest trends in the molecular engineering of these compounds were highlighted.

2

Improved wireless LED-based light emitters for photocatalytic oxidation in a slurry annular reactor

Aziz Zulkifly, Saari Mohd Mawardi, Zaini Mohd Aufa Hadi Putera, Nadzri Nurul A’in, Chin Sim Yee

Przegląd Elektrotechniczny

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2023

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R. 99, nr 8

170--174

EN

n this work, a custom-built ferrite rod was designed to replace the commercial ferrite drum core in a conventional wireless light emitter driven by wireless power transfer for photocatalytic oxidation of wastewater. Simultaneous improvement in coupling coefficient and quality factor was achieved, allowing maximum energy transfer. A coupling coefficient of 0.024 was achieved at the center of the field coil at zero angular misalignment for a coil quality factor of 74 measured at the switching frequency of 185 kHz. In addition, the emitter irradiation intensity could be regulated from 80 – 380 W/m2, a useful feature in the situation where high intensity promotes the recombination of electrons and holes.

PL

W tej pracy zaprojektowano niestandardowy pręt ferrytowy, który ma zastąpić komercyjny rdzeń bębna ferrytowego w konwencjonalnym bezprzewodowym emiterze światła napędzanym bezprzewodowym transferem energii do fotokatalitycznego utleniania ścieków.Osiągnięto jednoczesną poprawę współczynnika sprzężenia i współczynnika jakości, umożliwiając uzyskanie maksymalnej energii Współczynnik sprzężenia 0,024 został osiągnięty w środku cewki polowej przy zerowej niewspółosiowości kątowej dla współczynnika jakości cewki 74 mierzonego przy częstotliwości przełączania 185 kHz.W/m2, użyteczna cecha w sytuacji, gdy wysokie natężenie sprzyja rekombinacja elektronów i dziur.

3

Synthesis and Characterization of Photocatalyst Nanocomposite for the Degradation of Organic Pollutants in Wastewater

Ratnawulan, Rahmadhani Detty, Fauzi Ahmad, Jonuarti Riri, Supian Faridah Lisa, Jhora Fadhila Ulfa

Journal of Ecological Engineering

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2023

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Vol. 24, nr 12

388--396

EN

Various efforts can be made to obtain clean water in the environment by utilizing semiconductor technology. This study aims to inform the synthesis and characterization of MnO2/CuO/Fe2O3 photocatalyst for crystal violet degradation in wastewater. Nanocomposite was synthesized through a sol-gel process with three semiconductor materials doped. X-ray diffraction (XRD) was employed to analyze the nanocomposite structure and determine crystal size. Fourier transform infrared (FTIR) was used to provide functional groups in the nanocomposite. A scanning electron microscope (SEM) can characterize surface morphology and particle size. The results of the SEM show that an increase in sintering temperature causes the smallest particle sizes to be 54.79 nm. The result of characterization using the ultraviolet-visible (Uv-Vis) spectrophotometry analysis the most effective band gap value in photocatalyst activity was 1.36 eV. The optimum percent of degradation MnO2/CuO/Fe2O3 catalyst was 50.40% for the sample at a temperature of 400 °C under irradiation with sunlight for six hours. Test results show that increased sintering temperature increased the photocatalytic activity.

4

Hydrothermal Synthesis and Characterization of Sodium Bismuth Titanatefor Photocatalytic Applications

Mesrar Mohammed, Elbasset Abdelhalim, El Mrabet Imane, Zaitan Hicham, Abdi Farid, Echatoui Nor-Said, Lamcharfi Taj-dine

Journal of Ecological Engineering

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2023

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Vol. 24, nr 10

185--197

EN

Sodium bismuth titanate (Na0.5Bi0.5TiO3, abbreviated NBT) ceramics underwent concurrent successful synthesis on the basis of the hydrothermal method. A selected low-temperature process of thermal treatment was conducted to obtain a highly dense morphology, produced from high purity carbonates and oxides serving as initial precursors. The presence of well-crystallized NBT in the rhombohedral phase was also found at hydrothermal temperatures of 200 °C. X-ray diffraction (DRX), Raman spectroscopy, Infrared spectroscopy (IR), and Scanning electron microscopy (SEM) analysis enabled to verify the structure, phase, morphology, and composition of the used samples. NBT ceramics exhibit features specific to relaxor ferroelectrics, with a diffusion exponent γ of up to 1.5 to promote their applications in micro-electromechanical and energy harvesting systems. The photocatalytic behaviors of NBT powders have been assessed by means of the degradation of methylene blue (MB) through UV-light irradiation. The samples prepared with precursors having a Na/Bi ratio of 0.5/0.5 showed the highest methylene blue (MB) photodegradation rate of 100% under UV irradiation for 420 minutes. In addition, photocatalytic activities under different masses and pH values were discussed for the first time. In addition, the photocatalyst has excellent stability, due to the larger particle size and surface area, which opens up new possibilities for the design of multi-component photocatalysts for future applications. The photocatalytic mechanism for the degradation of organic dyes (MB) has been principally assigned to the photoreduction process caused by superoxide radical anions (•O2−) and hydroxyl radicals (•OH).

5

Fixed Bed System Packed with Porous Materials for Removal of Organic Dye from Wastewater

Cho Young-Sang, Sung Sohyeon

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

51--56

EN

Fixed beds were adopted for removal of organic dye from water by photocatalytic decomposition or adsorption. To this end, macroporous titania or silica micro-particles were synthesized from emulsions as micro-reactors and packed in the bed. During feeding aqueous methylene blue solution, UV light was irradiated for generation of active radicals for removal of dye by photocatalytic decomposition. Porous silica particles were also used as adsorbents in the bed for continuous adsorption of organic dye. For regeneration of the porous titania or silica particles, rinsing with fresh water was carried out before repeated cycles.

6

Design of UVA-LED concentric glass tube microreactor and evaluation of photocatalysis with simultaneous adsorption and hydrodynamic cavitation for fluorescent dye degradation

Sundar Kaviya Piriyah, Kanmani Sellappa

Environment Protection Engineering

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2022

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Vol. 48, nr 1

5--22

EN

A slurry UVA-LED concentric glass tube reactor (CGTR) with micro-depthof 2 mm was designed for plug flow behaviour (length/effective diameter = 150). The reactor design considered uniform radial concentration and hydrodynamic cavitation. The 100% Acridine Orange dye (3.77×10-5 M) was removed within 35 min at the graphene oxide dose of 0.3 g/dm3 and initial pH 11. It was observed that hydrodynamic cavitation shortened the reaction time and enhanced the apparent reaction rate constant from 0.022 to 0.109 min-1. Further, the degradation pathway showed that decolourized dye solution consisted of ethylenedione (34%), indicating the oxidative reaction occurred.

7

Innowacyjne cementowe kompozyty fotokatalityczne

Jackiewicz-Rek Wioletta, Chilmon Karol

Materiały Budowlane

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2021

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nr 3

48--50

8

Synthesis of an optical catalyst for cracking contaminating dyes in the wastewater of factories using indium oxide in nanometer and usage in agriculture

Ahmed Ishaq F. E., El-Shenawy Ahmed I., Refat Moamen S.

Polish Journal of Chemical Technology

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2019

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Vol. 21, nr 4

98--105

EN

Herein, the photocatalytic degradation of the Congo Red (CR) and Crystal Violet (CV) dyes in an aqueous solution were discussed in the presence of an indium(III) oxide (In2O3) as optical catalyst efficiency. The caproate bidentate indium(III) precursor complex has been synthesized and well interpreted by elemental analysis, molar conductivity, Fourier transform infrared (FT-IR), UV-Vis, and thermogravimetric (TGA) with its differential thermogravimetric (DTG) studies. The microanalytical and spectroscopic assignments suggested that the associated of mononuclear complex with 1:3 molar ratio (M3+:ligand). Octahedral structure is speculated for this parent complex of the caproate anion, CH3(CH2)4COO− ligand. The In2O3 NPs with nanoscale range within 10–20 nm was synthesized by a simple, low cost and eco-friendly method using indium(III) caproate complex. Indium oxide nanoparticles were formed after calcination of precursor in static air at 600°C for 3 hrs. The structural, grain size, morphological and decolorization efficiency of the synthesized NPs were characterized using the FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analyses. It was worthy mentioned that the prepared In2O3 NPs showed a good photodegradation properties against CR and CV organic dyes during 90 min.

9

Effects of Al doping on defect behaviors of ZnO thin film as a photocatalyst

Yu Fucheng, Hu Hailong, Wang Bolong, Li Haishan, Song Tianyun, Xu Boyu, He Ling, Wang Shu, Duan Hongyan

Materials Science Poland

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2019

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Vol. 37, No. 3

437--445

EN

Al doped ZnO (AZO) thin films were prepared on silica substrates by sol-gel method. The films showed a hexagonal wurtzite structure with a preferred orientation along c-axis. Suitable Al doping dramatically improved the crystal quality compared to the undoped ZnO films. Dependent on the Al dopant concentration, the diffraction peak of (0 0 2) plane in XRD spectra showed at first right-shifting and then left-shifting, which was attributed to the change in defect concentration induced by the Al dopant. Photocatalytic properties of the AZO film were characterized by degradation of methyl orange (MO) under simulated solar light. The transmittance of the films was enhanced by the Al doping, and the maximum transmittance of 80 % in the visible region was observed in the sample with Al concentration of 1.5 at.% (mole fraction). The film with 1.5 at.% Al doping achieved also maximum photocatalytic activity of 68.6 % under solar light. The changes in the film parameters can be attributed to the variation in defect concentration induced by different Al doping content.

10

Preparation, Characterization, and Application of N,S-codoped TiO2/Montmorillonite Nanocomposite for the Photocatalytic Degradation of Ciprofloxacin: Optimization by Response Surface Methodology

Massoudinejad M., Paseban A., Yazdanbakhsh A., Nabid M. R.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 4

66--74

EN

An N,S-codoped TiO2/Montmorillonite nanocomposite, as a photocatalyst, was synthesized in the sol-gel method and used for the degradation of ciprofloxacin (Cip) in an aqueous solution. N,S-codoped TiO2/Montmorillonte was characterized by powder X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), and X-ray fluorescence (XRF) analyzes. A central composite design (CCD) was used to optimize the variables for the removal of Cip by the N,S-codoped TiO2/Montmorillonite. A maximum decomposition of 92% of Cip was achieved in optimum conditions. The band gap value for the nanocomposite was 2.77 eV. Moreover, with the use of nanocomposite in the four consecutive runs, the final removal efficiency was 66%. The results show that the N,S-codoped TiO2/ Montmorillonite under simulated sunlight irradiation can be applied as an effective photocatalyst for the removal of Cip from aqueous solutions.

11

Fabrication and characterization of Zn doped CuO nanofiber using newly designed nanofiber generator for the photodegradation of methylene blue from textile effluent

Sethuraman R. G., Venkatachalam T., Kirupha S. D.

Materials Science Poland

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2018

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Vol. 36, No. 3

520--529

EN

High aspect ratio, Zn doped copper oxide (Zn-CuO) nanofibers have been fabricated employing a newly designed electrospun coating unit using copper acetate, sodium hydroxide and polyethylene glycol in aqueous state. The prepared Zn doped copper oxide (Zn-CuO) nanofibers were sintered at 400 °C, 500 °C and 600 °C separately and characterized using X-ray diffraction XRD, Fourier transformation infrared spectroscopy FT-IR, scanning electron microscopy SEM, energy dispersive spectroscopy EDS. The average crystallite size was in the range of 28 nm to 30 nm. Optical properties of Zn-CuO nanofibers were analyzed using UV-DRS studies which showed a blue shift in the absorption band. An increase in band gap with the increase in postannealing temperature was observed due to the blue shift in absorption edge of CuO causing enhanced photodegradation. The catalytic properties of the CuO nanofibers were tested using methylene blue in aqueous medium. The influences of parameters responsible for high photodegradation were optimized and the rate of the photodegradation process was calculated using photodegradation kinetics. The reusability test was conducted to find the stability of the fabricated Zn-CuO nanofibers.

12

Temperature study of magnetic resonance spectra of co-modified (Co,N)-TiO2 nanocomposites

Guskos N., Typek J., Zolnierkiewicz G., Guskos A., Berczynski P., Dolat D., Mozia S., Aidinis K., Kruk K., Morawski A. W.

Materials Science Poland

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2016

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Vol. 34, No. 2

242--250

EN

The (nCo,N)-TiO2 (n = 1, 5 and 10 wt.% of Co) nanocomposites were investigated by magnetic resonance spectroscopy in 4 K to 290 K range. Analyses of ferromagnetic/electron paramagnetic resonance (FMR/EPR) spectra in terms of four Callen lineshape components revealed the existence of two types of magnetic centers, one derived from metallic cobalt nanoparticles in superparamagnetic (SPM) phase and the other from cobalt clusters in the TiO2 lattice. Additionally, at low temperature the EPR spectrum arising from Ti3+ ions was also registered. Both relaxations of the Landau-Lifshitz type and the Bloch-Bloembergen type played an important role at high temperature in determining the linewidths and the latter relaxation was prevailing at low temperature. Analysis of the integrated intensity showed that the SPM signal is due to small size FM cobalt nanoparticles while the paramagnetic signal from Co clusters originates from those nanoparticles in which the concentration of magnetic polarons is below the percolation threshold.

13

Fotoaktywne materiały budowlane

Janus M.

Materiały Budowlane

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2015

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nr 6

102--104

PL

W artykule przedstawiono wybrane wyniki badań dotyczące fotokatalitycznej aktywności modyfikowanych materiałów budowlanych. Testowanymi materiałami były płytki betonowe, płytki gipsowe oraz cegły. Modyfikacja polegała na dodaniu 1, 5, 10 i 20% wag. fotokatalizatorów na bazie TiO2 do betonu, gipsu i gliny. Fotokatalizatory otrzymano w wyniku modyfikacji TiO2 węglem i azotem. Źródłem węgla był metanol, etanol lub izopropanol, zaś źródłem azotu był amoniak. Temperatura modyfikacji wynosiła 100, 300 i 600 °C. Fotoaktywność płytek betonowych i gipsowych była testowana podczas rozkładania barwnika monoazowego Czerwień Reaktywna 198, natomiast fotoaktywność cegieł podczas rozkładania kwasu oleinowego. Najwyższą fotokatalityczną aktywność osiągały materiały budowlane z 10% wagowym dodatkiem fotokatalizatorów. Do modyfikacji betonu najlepszym fotokatalizatorem był fotokatalizator modyfikowany metanolem w 300 °C, do modyfikacji gipsu fotokatalizator modyfikowany etanolem w 100 °C, zaś do modyfikacji cegieł najlepszy okazał się TiO2 modyfikowany metanolem w 100 °C.

EN

In this study the photocatalytic activity of modified building materials were presented. Concrete plates, gypsum plates and bricks were tested. 1, 5, 10 and 20wt% of photocatalyst on TiO2 base were introduced to concrete, gypsum and clay. Photocatalysts were obtained by modification of TiO2 by carbon and nitrogen. The source of carbon were: methanol, ethanol, isopropanol and the source of nitrogen was gaseous ammonia. Modification temperature amounted 100, 300 and 600 °C. Photocatalytic activity of concrete and gypsum plates were tested during monoazo dye Reactive Red 198 decomposition. Photocatalytic activity of brick was tested during oleic acid decomposition. The best photocatalytic activity had building materials with 10wt% of photocatalysts addition. For concrete modification photocatalyst modified by methanol at 300 °C was the best, for gypsum - photocatalyst modified by ethanol at 100 °C and for bricks the best one was photocatalyst modified by methanol at 100 °C.

14

Laboratoryjny reaktor do badania reakcji fotokatalitycznych w układzie ciekłe reagenty - stały katalizator

Słomkiewicz P. M., Szczepanik B.

Aparatura Badawcza i Dydaktyczna

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2015

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T. 20, nr 1

24-35

PL

W pracy przedstawiono budowę i zasadę działania laboratoryjnego reaktora do badania reakcji fotokatalitycznych w układzie ciekłe reagenty - stały katalizator. Konstrukcja reaktora umożliwia pobieranie próbek z mieszaniny reakcyjnej oraz doprowadzanie do mieszaniny reakcyjnej gazów, w tym gazów obojętnych

EN

The construction and the principle of operation of the laboratory reactor for testing photocatalyst reactions in the liquid reagents - the solid catalyst system have been described in the presented paper. Construction of reactor enables sampling of the reaction mixture and supplying to the reaction mixture of gases and inert gases too.

15

Fotokatalizatory hybrydowe z matrycą TiO2 aktywowaną ftalocyjaninami lantanowców

Słota R., Dyrda G., Galbas M., Mele G.

Chemik

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2014

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Vol. 68, nr 4

385--390

PL

Przedstawiono wyniki badań aktywności nowego typu fotokatalizatorów hybrydowych z matrycą TiO2 (anataz) impregnowaną diftalocyjaninami lantanowców (LnPc2), w procesie fotoutleniania 4-nitrofenolu w fazie wodnej. Stwierdzono, że w obecności odpowiedniego sensybilizatora ftalocyjaninowego szybkość degradacji 4-NP może zwiększyć się nawet 4-krotnie w porównaniu z czystym anatazem. Najbardziej efektywne były układy zawierające kompleksy Gd i Ho.

EN

Research results on the activity of novel hybrid photocatalysts with a TiO2 (anatase) matrix impregnated with lanthanide diphthalocyanines (LnPc2) in photooxidation of 4-nitrophenol in the water phase have been reported. It was found that in presence of an appropriate phthalocyanine sensitizer the degradation rate of 4-NP might have increased even four-fold, as compared to bareanatase. Systems containing complexes of Gd and Ho were the most effective ones.

16

Reaktory fotokatalityczne do oczyszczania wody i ścieków

Brożek P., Janus M., Morawski A. W., Mozia S.

Przemysł Chemiczny

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2013

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T. 92, nr 10

1929-1936

PL

Wśród najnowszych technologii, intensywnie rozwijanych w ostatnich kilkudziesięciu latach, znalazła się fotokataliza, będąca jednym z zaawansowanych procesów utleniania. Przedstawiono podstawy fotokatalizy heterogenicznej oraz przegląd opisanych w literaturze reaktorów fotokatalitycznych, stosowanych do usuwania zanieczyszczeń z wody. Omówiono podział fotoreaktorów, z uwzględnieniem sposobu pracy, źródła promieniowania oraz sposobu wprowadzenia fotokatalizatora. Przedstawiono przykładowe reaktory laboratoryjne oraz zaprezentowano obecny stan badań i rozwoju w obszarze reaktorów pilotażowych.

EN

A review, with 74 refs., of lab. and pilot-scale photoreactors with various sources of irradn. and manners of photocatalyst application.

17

Proces fotoktalityczny wybranych sulfonamidów w obecności TiO2, FeCl3 i TiO2/FeCl3

Ziemiańska J., Papla P., Baran W., Adamek E., Sobczak A., Lipska I.

Proceedings of ECOpole

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2013

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Vol. 7, No. 1

427--434

PL

Powszechne stosowanie chemioterapeutyków niesie ze sobą wiele negatywnych skutków. Są one używane w weterynarii, medycynie, hodowli ryb, a także przy uprawie roślin. Sulfonamidy są przykładem takich leków. Są bakteriostatycznymi chemioterapeutykami, które obecnie są głównie stosowane w weterynarii. Gromadząc się w różnorodnych organizmach, często są wobec nich toksyczne. Poszukuje się różnorodnych metod, które mają na celu przeciwdziałanie rosnącemu zanieczyszczeniu środowiska. Jedną ze skutecznych metod jest fotokataliza, która zachodzi przy udziale katalizatora i w obecności promieniowania elektromagnetycznego. Związek organiczny poddany działaniu procesowi fotokatalitycznemu ulega rozkładowi, a następnie całkowitej mineralizacji. Celem pracy było zbadanie skuteczności procesu fotokatalitycznego w obecności wybranych sulfonamidów przy zastosowaniu wybranych układów katalitycznych. Procesy fotokatalityczne badano przy użyciu katalizatora TiO2 P25 Degussa Aeroxide®, FeCl3 oraz mieszaniny TiO2/FeCl3. Fotokataliza zachodziła we wszystkich układach katalitycznych. Stwierdzono, że mieszanina TiO2/FeCl3 jest najbardziej efektywnym układem katalitycznym. Dynamika procesu fotokatalitycznego była charakterystyczna dla reakcji pierwszorzędowych.

EN

The widespread use of chemotherapeutic carries with it many negative effects. They are used in veterinary, medicine, fish farming and the cultivation of plants. Sulfonamides are an example of such drugs. They are bacteriostatic chemotherapeutics, which are now mainly used in veterinary medicine. Cumulating at a variety of organisms, are often toxic to them. Aim is to find a variety of methods which prevent the increasing environmental pollution. One of the most effective methods is photocatalysis, which occurs with the participation of the catalyst in the presence of electromagnetic radiation. Organic compound subjected to photocatalysis is degraded, then undergoes the total mineralization. The aim of this study was to examine the effectiveness of the process of photocatalysis in the presence of selected sulfonamides using the selected catalytic systems. Photocatalytic processes have been studied using the catalyst TiO2-P25 Degussa Aeroxide®, and a mixture of FeCl3 and TiO2/FeCl3. Photocatalysis occurred in all the catalytic systems. It was found that the mixture TiO2/FeCl3 is the most efficient catalytic system. The dynamics of the process of photocatalytic reaction was typical for the first order reaction.

18

Proces fotokatalityczny z udziałem katalizatora immobilizowanego

Ziemiańska J., Baran W., Adamek E., Sobczak A., Lipska I.

Proceedings of ECOpole

|

2013

|

Vol. 7, No. 2

765--771

PL

Coraz większe zanieczyszczenie środowiska sprawia, że poszukiwane są skuteczne metody jego oczyszczania. W tym celu stosowane są różnorodne procesy fizykochemiczne i biologiczne. Jednym ze skutecznych sposobów degradacji szkodliwych związków jest fotokataliza, która należy do metod zaawansowanego utleniania (AOP). Dzięki tej technice dochodzi do rozkładu wielu substancji organicznych, w tym i leków w wyniku utleniania za pomocą generowanych w środowisku reakcji rodników hydroksylowych. Celem pracy było opracowanie efektywnej i zarazem taniej metody usuwania wybranych związków, wykorzystując proces fotokatalityczny. Stąd też został wykorzystany komercyjny katalizator TiO2-P25, immobilizowany na włóknie szklanym. Proces prowadzony był w otwartych reaktorach, które były naświetlane promieniowaniem UV-A. Optymalizację katalizatora prowadzono na podstawie badań fotokatalitycznej dekoloryzacji barwnika Acid Orange 7. W wyniku badań została porównana kinetyka procesów prowadzonych z suspensją i z immobilizowanym katalizatorem. Immobilizacja fotokatalizatora pozwala na znaczne ograniczenie jego zużycia.

EN

Growing environmental pollution caused that more and more efficient methods of sewage treatment are being developed. Various physicochemical and biological processes are used to achieve that aim. Photocatalysis is one of the most efficient methods of degradation of harmful chemical compounds. It is one of the advanced oxygenation processes (AOP). Thanks to that technique most of the organic compounds, including medicines is degraded as a result of reactions of free hydroxide radicals in the environment. Target of the research was to develop effective and cost efficient method of eradication of selected chemical compounds using photocatalytic process. To achieve that aim, commercial TiO2-P25 catalyst immobilized on fiberglass has been used. Reaction has been conducted in open reactors, which were irradiated with UV radiation. Method has been optimized as a result of studies on dye shade changes of Acid Orange 7 dye using the same method. In the result of studies, kinetics of reactions with suspended and immobilized catalyst were compared. Photocatalytic reaction with immobilization allows for lower catalyst use.

19

Photocatalytic performance of titania nanospheres deposited on graphene in coumarin oxidation reaction

Wojtoniszak M., Zielinska B., Kalenczuk R. J., Mijowska E.

Materials Science Poland

|

2012

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Vol. 30, No. 1

32--38

EN

In this paper, we present a study on enhanced photocatalytic performance of TiO2 nanospheres deposited on graphene (n-TiO2-G) in a process of coumarin oxidation. The enhancement of the photoactivity has been observed in respect to commercial TiO2 P25. The presented material was prepared in two steps: (i) hydrolysis of titanium (IV) butoxide (TBT) in ethanol solution with simultaneous deposition on graphene oxide (GO) and (ii) calcination of TiO2-GO to form anatase-TiO2 and reduce GO to graphene. The nanomaterial was characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), Fourier-Transformed Infrared spectroscopy and Raman spectroscopy. In the presented photocatalytic process the fluorescence was used to detect-OH formed on a photo-illuminated n-TiO2-G surface using coumarin which readily reacted with -OH to produce highly fluorescent 7-hydroxycoumarin.

20

Removal of natural organic matter from potable water using photo-catalytic membrane reactor

Kumakiri I., Simon Ch., Szczepanowicz K., Wodka D., Nowak P., Szyk-Warszyńska L., Warszyńsk P.

Physicochemical Problems of Mineral Processing

|

2010

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Vol. 45

73-84

EN

The application of photocatalysis combined with membrane filtration for the oxidation of humic acid substances (HA) which is one of the major natural organic matters (NOMs) is discussed in this paper. Theoretical model shows a potential advantage of photo-catalytic filtration under low flux conditions. Cross-flow filtration is applied for HA removal using a TiO2 membrane under UV conditions. An increase of the flux through the membrane was observed by applying UV light.