Wyniki wyszukiwania - BazTech

1

Preparation and characterization of BiOCl/TiO2/MMTcomposite materials

Tuo Biyang, Shi Xiulong, Tian Jinwang, Wang Jianli

Materials Science Poland

|

2023

|

Vol. 41, No. 2

354--367

EN

To broaden the light response range of TiO2 and improve its photocatalytic activity, BiOCl/ TiO2 /MMT composite materials(BTMC) with outstanding photocatalytic performance were prepared by the sol-gel method with montmorillonite (MMT) asthe supporting material, tetrabutyl titanate as titanium source and, bismuth nitrate pentahydrate as the bismuth source. Theproperties of the prepared materials were characterized by X-ray diffractometer (XRD), surface and porosity analysis (BET),scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM),X-ray photoelectron spectrometry (XPS), and ultraviolet-visible diffuse reflection spectroscopy (UV-Vis DRS). When the Bi/Timolar ratio was 20%, the composite material exhibited a slit mesoporous structure, and its specific surface area was 109.02m2/g, with optimum photocatalytic activity. TiO2 and BiOCl formed the type-II heterojunction on the surface of MMT, whichfacilitates the transfer of photogenerated electrons and holes, thus enhancing the photocatalytic activity of BTMC-20. Theresults of this study indicated that BTMC-20 is a promising photocatalytic composite material and has better photocatalyticproperties under visible light.

2

Photocatalytic TiO2 Nanostructures Developed on the Grade 2 Ti Material

Tarcea Claudia I., Pantilimon Cristian Mircea, Coman George, Turcanu Andreea A., Predescu Andra Mihaela, Matei Ecaterina, Berbecaru Andrei-Constantin, Predescu Cristian

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 3

1079--1084

EN

The research focused on TiO2 nanostructures environmental applications due to the special characteristics that displayed degradation of the organic compounds into environmentally friendly products through exposure to UV light. The protocol behind obtaining the nanostructures involved the use of a Ti material exposed to alkaline treatment and advanced oxidation using NaOH solution and acetone. These studied nanostructures were analyzed extensively by using methods such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) for characterizing the elements, compounds and morphological properties of the material. These differences in morphology is attributed to different NaOH solution concentrations. The Ti sheets were immersed into NaOH and acetone mixed solutions for 72 hours. The best results were recorded by using 30% NaOH solution. After obtaining the 3D structures, which improve specific surface and contact area with the environment, the samples were tested under UV light in order to degrade methylene blue in order to determine their photocatalytic performance.

3

Cu-doped TiO2 brookite photocatalyst with enhanced visible light photocatalytic activity

Zou Yunling, Huang Xianshou, Yu Tao, Tong Xiaoqiang, Li Yan, Lian Xiaoxue, Xie Yao, Huang Jiaming, He Wei, Li Wenxin

Materials Science Poland

|

2020

|

Vol. 38, No. 4

644--653

EN

Cu-doped TiO2 having a brookite phase and showing enhanced visible light photocatalytic activity was synthesized using a mild solvothermal method. The as-prepared samples were characterized by various techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity of Cu-doped brookite TiO2 nanoparticles was evaluated by photodegradation of methylene blue under visible light irradiation. The X-ray diffraction analysis showed that the crystallite size of Cu-doped brookite TiO2 samples decreased with the increase of Cu concentration in the samples. The UV-Vis diffuse reflectance spectroscopy analysis of the Cu-doped TiO2 samples showed a shift to lower energy levels in the band gap compared with that of bare phase brookite TiO2. Cu doped brookite TiO2 can obviously improve its visible light photocatalytic activity because of Cu ions acting as electron acceptors and inhibiting electron-hole recombination. The brookite TiO2 sample with 7.0 wt.% Cu showed the highest photocatalytic activity and the corresponding degradation rate of MB (10 mg/L) reached to 87 % after visible light illumination for 120 min, much higher than that of bare brookite TiO2 prepared under the same conditions (78 %).

4

Usuwanie niejonowego surfaktantu z wód ściekowych z wykorzystaniem synergicznego działania metod zaawansowanego utleniania

Kuźmiński Kamil, Zając Kamila, Janus Magdalena

Forum Eksploatatora

|

2019

|

Nr 4 (103)

44-50

PL

Jednym z głównych zanieczyszczeń środowiska wodnego są związki powierzchniowo czynne, stosowane intensywnie zarówno w gospodarstwach domowych jako środki piorące i myjące, jak i w wielu gałęziach przemysłu. Wykorzystuj się je przy produkcji tworzyw sztucznych, żywic syntetycznych, farb, lakierów celulozy, papieru, a także przy produkcji żywności, w kosmetyce, farmacji, medycynie i fotografice [1] Ich negatywne działanie wynika przede wszystkim z ich pośredniej szkodliwości dla ekosystemów wodnych. Surfaktanty ułatwiają rozpuszczanie w wodzie substancji toksycznych trudno rozpuszczalnych lub nierozpuszczalnych w wodzie. Powodują także pienienie wody, pogarszając warunki dyfuzji tlenu. Konsekwencje obniżonego stężenia tlenu w wodzie dotyczą zarówno zamierania życia biologicznego, jak i pogorszenia zdolności do samooczyszczania się zbiorników wodnych [2,3]. Dodatkowo doniesienia literaturowe wskazują, że związki powierzchniowo czynne o charakterze niejonowym mogą odznaczać się bezpośrednią toksycznością, silniejszą niż surfaktanty jonowe [4]. Jednym z przedstawicieli powszechnie stosowanych surfaktantów niejonowych jest Triton X-100, należący do typu politoksylowanych alkilofenyli. Związki te są podejrzewane o działanie zaburzające wydzielanie wewnętrzne organizmów wodnych.

5

Enhancement photocatalytic activity of spinel oxide (Co, Ni)3O4 by combination with carbon nanotubes

Kahdum B. J., Lafta A. J., Johdh A. M.

Polish Journal of Chemical Technology

|

2017

|

Vol. 19, nr 3

61--67

EN

In this study, some types of composites consisting of multi-walled carbon nanotubes (MWCNTs) and spinel oxide (Co, Ni)3 O4 were synthesized by simple evaporation method. These composites were characterized by UV–Vis diffuse reflectance spectroscopy, X-rays diffraction(XRD), Scanning electron microscopy (SEM) and specific surface area(SBET ). The photocatalytic activity of the prepared composites was investigated by the following removal of Bismarck brown G (BBG) dye from its aqueous solutions. The obtained results showed that using MWCNTs in combination with spinel oxide to produced composites (spinel/MWCNTs) which succeeded in increasing the activity of spinel oxide and exhibited higher photocatalytic activity than spinel oxide alone. Also it was found that, multiwalled carbon nanotubes were successful in increasing the adsorption and improving the activity of photocatalytic degradation of Bismarck brown G dye(BBG). The obtained results showed that spinel/MWCNTs was more active in dye removal in comparison with each of spinel oxide and MWCNTs alone under the same reaction conditions. Also band gap energies for the prepared composites showed lower values in comparison with neat spinel. This point represents a promising observation as these composites can be excited using a lower energy radiation sources.

6

Combination of mesoporous titanium dioxide with MoS2 nanosheets for high photocatalytic activity

Karimi L.

Polish Journal of Chemical Technology

|

2017

|

Vol. 19, nr 2

56--60

EN

This study presents a facile approach for the preparation of MoS2 nanosheet decorated by porous titanium dioxide with effective photocatalytic activity. Mesoporous titanium dioxide nanostructures first synthesized by a hydrothermal process using titanium (III) chloride and then the MoS2 /TiO2 were prepared through mixing of MoS2 nanosheet with mesoporous titanium dioxide under ultrasonic irradiation. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The results showed that the nanocomposite has mesoporous structure with specific surface area of 176.4 m2 /g and pore diameter of 20 nm. The as-prepared MoS2 /TiO2 nanocomposites exhibited outstanding photocatalytic activity for dye degradation under sunlight irradiation, which could be attributed to synergistic effect between the molybdenum disulfide nanosheet and mesoporous titanium dioxide. The photocatalytic performance achieved is about 2.2 times higher than that of mesoporous TiO2 alone. It is believed that the extended light absorption ability and the large specific surface area of the 2D MoS2 nanosheets in the nanocomposite, leading to the enhanced photocatalytic degradation activity.

7

Facile synthesis of hierarchical ZnO microstructures with enhanced photocatalytic activity

Miao L., Shi B., Nawrat S., Mu C, Qi K.

Materials Science Poland

|

2017

|

Vol. 35, No. 1

45--49

EN

Flower-like ZnO microstructures were successfully synthesized via a facile hydrothermal route without using any surfactants. The morphology of these microstructures can be easily controlled by adjusting the pH of the reaction solution. The possible growth mechanism of ZnO hierarchical microstructures was proposed based on the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) results. The photocatalytic activity studies of ZnO nanocrystals demonstrated their excellent photocatalytic performance in degrading aqueous methylene blue (MB) under UV-A light irradiation. This higher photocatalytic activity of the ZnO nanoplates was mainly attributed to the exposed facets with the higher surface energy.

8

Effect of the structure on biological and photocatalytic activity of transparent titania thin-film coatings

Wojcieszak D., Mazur M., Kaczmarek D., Poniedziałek A., Domanowski P., Szponar B., Czajkowska A., Gamian A.

Materials Science Poland

|

2016

|

Vol. 34, No. 4

856--862

EN

In this work, the effect of titanium dioxide (TiO2) thin film microstructure on photocatalytic and biological activity was described. The films were prepared by low-pressure and high-energy magnetron sputtering processes. The structural investigations performed by X-ray diffraction revealed that the films from both the processes were nanocrystalline. It was found that TiO2 prepared by low-pressure process had the anatase structure with crystallites in size of 20 nm, while the film deposited in high-energy process had the rutile form with crystallites in size of 5 nm. The analysis of surface topography with the aid of optical profiler showed that all prepared films were homogenous and their roughness was lower than 1 nm. The wettability studies revealed hydrophilic nature of both films. The values of water contact angle obtained for anatase and rutile films were equal to 40° and 49°, respectively. Both types of the thin films were photocatalitycally active, but rutile exhibited higher decomposition rate as compared to anatase. During the photocatalytic reaction in the presence of TiO2-rutile film after 12 hours of UV-Vis irradiation 30 % of phenol was decomposed, whereas in case of TiO2-anatase it was only 10 %. Moreover, the influence of as-deposited coatings on the growth of selected microbes (Staphylococcus aureus, Escherichia coli, Candida albicans) was examined. It was found that the structural properties of TiO2 had an effect on biological activity of these films.

9

Fotoaktywne materiały budowlane

Janus M.

Materiały Budowlane

|

2015

|

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.

10

Aktywne środowiskowo nawierzchnie z betonowej kostki brukowej

Doering M., Mrozik Ł.

Materiały Budowlane

|

2015

|

nr 5

69--70

PL

W artykule omówiono wybrane rozwiązania materiałowe, takie jak nawierzchnie z elementów ażurowych. Szczególną uwagę skupiono na kostce brukowej z nanokrystalicznym dwutlenkiem tytanu (TiO2). Przedstawiono wybrane właściwości tych wyrobów oraz techniczne i ekonomiczne aspekty popularyzacji tej technologii.

EN

In this article, some selected material solutions such as openwork surfaces has been discussed. Particular attention is focused on brick with nanocrystalline titanium dioxide (TiO2). Selected properties of these products and technical and economic aspects related to popularization of this technology has been shown.

11

Preparation and photocatalytic activity of multi-walled carbon nanotubes/Mg-doped ZnO nanohybrids

Chen C. S., Xie X. D., Cao S. Y., Liu T. G., Lin L. W., Chen X. H., Liu Q. C., Kuang J. C., Xiao Y.

Materials Science Poland

|

2015

|

Vol. 33, No. 3

460--469

EN

Multi-walled carbon nanotubes/Mg-doped ZnO (MWNTs/Zn1-xMgxO) nanohybrids were prepared by co-precipitation method, and their photocatalytic activity for methyl orange (MO) was studied. Experimental results showed that Mg-doped ZnO nanoparticles were successfully deposited on the surface of MWNTs under annealing at 450 degrees C and 550 degrees C. The resultant MWNTs/Zn0.9Mg0.1O nanohybrids had better photocatalytic activity for degradation of methyl orange than pure ZnO: the rates of MO photodegradation were 100 % and 30 % for 1 h, respectively. The enhancement in the photocatalytic activity was attributed to the excellent electronic properties of MWNTs and Mg-doping.

12

Activated Charcoal Supported Cadmium Doped TiO2 for Photocatalytic and Antibacterial Applications

Prabha S., Chandraboss V. L., Kamalakannan J., Senthilvelan S.

International Letters of Chemistry, Physics and Astronomy

|

2015

|

Vol. 44

108--123

EN

The photocatalytic activity was studied under UV light using AC-Cd/TiO2 prepared via precipitation method and characterized by powder X-ray diffraction (XRD) , high resolution scanning electron micrographs (HR-SEM) with energy dispersive X-ray analysis (EDX), photoluminescence (PL) and Fourier transform Raman analysis (FT-RAMAN). The enhanced photo catalytic activity of the AC-Cd/TiO2 is demonstrated through photodegradation of methylene blue under UV light radiation at 365 nm. The mechanism of photocatalytic effect of AC-Cd/TiO2 nanocomposite material has been discussed Further its antibacterial activity against two gram positive and two gram negative bacterial strain is studied.

13

Photocatalytic Self-cleaning Synergism Optimization of Cotton Fabric using Nano SrTiO3 and Nano TiO2

Zohoori S, Karimi L, Nazari A.

Fibres & Textiles in Eastern Europe

|

2014

|

Vol. 22, no. 2 (104)

91--95

EN

Titanium dioxide (TiO2) and Strontium titanate (SrTiO3) are well-known photocatalysts. Today, the photocatalytic activity of dyes on fabrics has attracted much attention. Therefore in this study the photocatalytic activity of nano strontium titanate mixed with nano titania was examined while being coated on cotton fabric under UV irradiation at different nano material concentrations and various pHs. The Central Composite Design (CCD) was used for different variables based on Design Expert software. The crystal size and phase of nano titania and strontium titanate were characterised by XRD. The cotton fabrics stained with two common synthesised dyes were treated under 400 W UV irradiation for 30 hours and their self-cleaning properties were investigated by reflectance spectrophotometer. SEM photos show the pervasion of nano materials. The results show that samples treated with SrTiO3 and TiO2 have higher values of ΔE* as compared with those treated with TiO2 or SrTiO3 alone.

PL

Tytanian strontu SrTiO3 i dwutlenek tytanu TiO2 są dobrze znanymi fotokatalizatorami. Obecnie fotokatalityczna aktywność barwników w materiałach tekstylnych wzbudza ogólne zainteresowanie i dlatego w przedstawionych badaniach fotokatalityczna aktywność nanocząstek SrTiO3 zmieszanych z TiO2 i naniesionych na tkaninę bawełnianą badana była przy napromieniowaniu UV przy różnym stężeniu nanocząstek i różnym pH. W badaniach stosowano program Central Composite Design i Design Expert dla różnych zmiennych. Wielkości krystalitów i faza cząstek TiO2 i SrTiO3 były charakteryzowane za pomocą XRD. Tkaniny bawełniane barwione dwoma powszechnie stosowanymi barwnikami syntetycznymi były naświetlane promieniowaniem UV o mocy 400 W przez 30 godzin a następnie były badane ich właściwości samooczyszczające przy zastosowaniu spektrofotometru refleksyjnego. Zdjęcia SEM pokazują rozłożenie nanocząstek. Wyniki badań wykazały, że próbki zawierające TiO2 i SrTiO3 mają wyższe wartości ΔE* niż próbki zawierające tylko jeden rodzaj nanocząstek.

14

Investigation of the effect of heat treatment process on characteristics and photocatalytic activity of TiO2-UV100 nanoparticles

Behnajady M. A., Alamdari M. E., Modirshahla N.

Environment Protection Engineering

|

2013

|

Vol. 39, nr 1

33--46

EN

The effect of heat treatment process on crystallite size, phase content, surface area, band gap energy and photocatalytic activity of TiO 2-UV100 nanoparticles were investigated. Heat treated TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) isotherm and diffuse reflectance spectroscopy (DRS) techniques, and its photocatalytic activity was investigated in the removal of C.I. Acid Red 88 (AR88), an anionic monoazo dye of acid class, as a model contaminant. Heat treatment process at 600 °C causes an increase in crystallite size and band gap energy of TiO2-UV100 nanoparticles. The results indicate that the nanoparticles treated for 1 h at 600 °C show the highest photocatalytic activity which can effectively degrade AR88 under UV-irradiation. Increasing heat treatment temperature above 600 °C led to reduction in TiO2 photoactivity which may be related to the anatase-rutile phase transformation, increasing particle size and decreasing specific surface area. Removal efficiency of AR88 with heat treated TiO 2-UV100 nanoparticles was sensitive to the operational parameters such as catalyst dosage, pollutant concentration and light intensity.

15

Otrzymywanie, właściwości oraz aktywność fotokatalityczna cienkich filmów SiO2-TiO2 domieszkowanych wanadem

Nocuń M., Kwaśny S.

Materiały Ceramiczne

|

2012

|

T. 64, nr 4

478-484

PL

W pracy otrzymano cienkie filmy SiO2/TiO2 domieszkowane wanadem na podłożu szklanym techniką zol-żel zanurzeniowo-wynurzeniową. Skład chemiczny próbek badano przy pomocy spektroskopii fotoelektronów (XPS). Transmitancję scharakteryzowano używając spektrofotometru UV-VIS. Wyznaczono optyczną przerwę energetyczną dla otrzymanych filmów. Zbadano również efekt fotokatalityczny dla próbek. Żele otrzymane z zoli zostały scharakteryzowane przy pomocy spektroskopii w podczerwieni (FTIR). Zaobserwowano, że dodatek wanadu powoduje obniżenie przerwy energetycznej cienkich filmów SiO2/TiO2.

EN

In our investigation, V-doped SiO2/TiO2 thin films were prepared on glass substrates by the dip coating sol-gel technique. The chemical composition of the films was studied by photoelectron spectroscopy (XPS). Transmittances of the samples were characterized using a UV-VIS spectrophotometer. Subsequently the band-gap energy (Eg) was estimated for the films. The photocatalytic effect was investigated for the obtained samples. Gels obtained from sols were characterized by FTIR spectroscopy. It was found that the vanadium additive decreases the optical band gap of SiO2/TiO2 films.

16

Photodegradation of organic dyes over nickel distributed CNT/TiO2 composite synthesized by a simple sol-gel method

Chen M. L., Oh W. C.

Materials Science Poland

|

2011

|

Vol. 29, No. 2

112--120

EN

In this study, the multi-walled carbon nanotubes were oxidized by m-chlorperbenzoic acid followed by the reaction with titanium n-butoxide and nickel nitrate to prepare Ni distributed CNT/TiO2 composite by a simple sol-gel method. The functional groups formed on the surface of MWCNTs were analyzed by Fourier transform infrared spectroscopy. The prepared Ni distributed CNT/TiO2 composite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis. The photodegradation of methylene blue, methylene orange and rhodamine B solution under UV irradiation was employed to test the photocatalytic activity of the Ni distributed CNT/TiO2 composite. According to the results, Ni distributed CNT/TiO2 composite showed very excellent photocatalytic activity to decompose MB, MO and Rh.B solutions, due to the electron absorption effect of MWCNTs and electron trapping effect of nickel.

17

Sensitizing of Semiconducting Photocatalysts by Cyanine Pigment with Two Conjugated Chromophores

Kobasa l. M., Kondratyeva I. V.

Polish Journal of Chemistry

|

2008

|

Vol. 82, nr 8

1639-1639

EN

TiO2 and CdS based heterostructures (HS) with biscyanine – cyanine pigment comprising two conjugated chromophores as a sensitizer have been synthesized. Absorption spectra of HS have been analyzed and their photocatalytic activity (PA) in the reaction of methylene blue reduction was determined. Energy transformation and electron transferring processes induced by various spectral zones irradiation have also been described. It has been found that photocatalytic activity depends on the pigment concentration in HS. Interrelation between changes in PA and some important spectral parameters has also been determined.

18

Novel experimental setup for the determination of the photocatalytic stability and activity of pigments and coatings

Wanner M., Nothhelfer-Richter R., Schauer T.

Ochrona przed Korozją

|

2008

|

nr 3

74-77

EN

In the past photoactive pigments have been surface passivated to reduce the photoactivity and thereby to avoid chalking. In new applications highly photoactive types of these pigments are used on glass or ceramic substrates for self cleaning and pollution reduction purposes. This initiated attempts to develop photoactivity test devices. In this contribution a test chamber method is presented which is based on a previous setup. The samples are placed in a chamber where various climatic and atmospheric conditions can be applied and controlled including exposure to model pollutants. During irradiation by UV light a FTIR spectrometer records the amount of pollutants and their decomposition products. This technique does not only allow to follow the photoactivity of the pigment and pigmented coating regarding the decomposition of model pollutants, but also to determine the photocatalytic stability of coatings by detecting products of the decomposition of the polymeric binder.

PL

Pigmenty fotoaktywne były dawniej pasywowane powierzchniowo w celu zmniejszenia ich aktywności fotokatalitycznej i tym samym uniknięcia kredowania. W nowych zastosowaniach pigmenty o dużej aktywności fotokatalitycznej wykorzystuje się na podłoża szklane i ceramiczne, w celu uzyskania właściwości samoczyszczących i odporności na zabrudzenia. Takie wykorzystanie pigmentów zainicjowało próby opracowania urządzeń do badania fotoaktywności. Przedstawiono komorową metodę badawczą, opartą na wcześniej opracowanym urządzeniu. Próbki umieszcza się w komorze, w której można modelować i kontrolować różne warunki atmosferyczne, obejmujące narażenia na modelowe zanieczyszczenia. Za pomocą spektrometru FTIR rejestruje się, podczas naświetlania próbek promieniami UV, ilość zanieczyszczeń i produktów ich rozkładu. Metoda ta pozwala nie tylko na śledzenie fotokatalitycznej aktywności pigmentu i pigmentowanych powłok na podstawie rozkładu modelowych zanieczyszczeń, ale również na oznaczenie fotokatalitycznej stabilności powłok, poprzez wykrywanie produktów rozkładu polimeru spoiwa.

19

Modification of TiO2 with W(VI) Ions: Photocatalytic Activity and Some Other Properties of Materials

Kobasa I. M., Wlodarczyk R. P.

Polish Journal of Chemistry

|

2007

|

Vol. 81, nr 10

1785-1805

EN

New TiO2 based materials doped with W(VI) compounds have been synthesized.We recorded diffusion reflection and absorption spectra and determined phase composition of thematerials. It has been found that thematerials containing 0.01–5.0mass%of the dope exist in the crystalline form of anatase while 10 mass%of the dope leads to the rutile crystalline form.We determined parameters of both types of lattice and proposed explanation for difference in parameters of doped and not doped lattices. Dependence of photocatalytic activity (PA), catalytic activity (CA), electroconductivity sigma, and magnetic susceptibility chi of a sample on the dope content are similar and all of them have maximum at 0.01 mass % of the dope. It has been found that PA and CA linearly depend on sigma and chi . Character of such dependencies has also been explained. Our experimental results proved that the higher is PA of a sample, the higher CA it reveals. This correlation can be observed along the range of existence of anatase crystalline modification as long as formation of rutile lattice changes the basic factors governing PA and CA.

20

Influence of Admixtures of f-Elements on Photocatalytic,Electrophysical and Magnetic Properties of TiO2

Wlodarczyk L., Kobasa I.

Polish Journal of Chemistry

|

2007

|

Vol. 81, nr 4

591-598

EN

It has been shown that photocatalytic activity, surface electroconductivity, and magnetic susceptibility of TiO2 significantly depend on the character and concentration of f-element’s admixture as well as on the temperature and conditions of its thermo-treating. Admixtures of f-elements with variable valence and relatively smaller ionic radius are more effective to reach higher photocatalytic activity, surface electroconductivity, and magnetic susceptibility. Above mentioned parameters of TiO2 increase with addition of a small amount of f-elements as well as after thermo-treating of a sample at 673–873 K in the reducing medium. Photocatalytic activity, electroconductivity, and magnetic susceptibility decrease on the following conditions: increase of an admixture content, thermo-processing in the oxidizing medium or at higher temperature.