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wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: SILVER, GOLD, TIO2
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Photodegradation of phenol by UV/TiO2 and Vis/N,C-TiO2 processes: Comparative mechanistic and kinetic studies
PublikacjaPorównano drogę fotodegradacji w dwóch systemach badawczych: UV/TiO2 i Vis/N,C-TiO2. Zbadano efektywność degradacji fenolu, powstające produkty pośrednie oraz generowanie rodników hydoksylowych w przygotowanych układach badawczych. Wyniki badań wykazały porównywalne efektywności degradacji fenolu w zawiesinach: domieszkowany TiO2/Vis i TiO2 P-25/UV. Uzyskane wyniki wskazują również na odmienne drogi degradacji zanieczyszczeń w...
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SEM - Expanded polystyrene coated by TiO2 or SiO2-TiO2
Dane BadawczeData contain SEM images taken in SEM Hitachi SU8000 with voltage of 5.0 kV. SEM images show expanded plystyrene spheres coated by a thin layer of TiO2 or bilayer SiO2-TiO2.
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Silver complexes stabilized by large silanethiolate ligands – crystal structures and luminescence properties
PublikacjaBulky silanethiolate and disiladithiolate ligands were applied to synthesize one mononuclear and three trinuclear silver complexes including two cyclic “microclusters” and a linear tri-nuclear silanethiolate complex. All obtained compounds are characterized by X-ray diffraction and FT-IR. NMR and emission spectroscopies were used where possible. The first trinuclear anionic silver thiolate is structurally characterized. The influence...
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The ILs-assisted solvothermal synthesis of TiO2 spheres: the effect of ionic liquids on morphology and photoactivity of TiO2
PublikacjaEffect of the ionic liquid (IL) structure (chain length in the imidazolium cation) on morphology and photoactivity of TiO2 particles has been systematically investigated. The TiO2 microspheres have been successfully synthesized via facile solvothermal method assisted by ionic liquids, such as 1-butyl-3-methylimidazolium chloride [BMIM][Cl] and 1-decyl-3-methylimidazolium chloride [DMIM][Cl] using tetra-tert-butyl orthotitanate...
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Application of micellar electrokinetic chromatography for detection of silver nanoparticles released from wound dressing
PublikacjaThe recent emergence of nanotechnology has provided a new therapeutic modality in case of silver nanoparticles. Dressings containing silver form the basis for the treatment of burns and wounds, either acute or chronic ones. The aim of the study was to examine silver release from the different wound dressings: commercially available (Atrauman Ag, Aqua- cel Ag) and experimental (FKDP-AgNPs) using MEKC. In order to characterize prepared keratin...
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The effect of microemulsion composition on the morphology of Pd nanoparticles deposited at the surface of TiO2 and photoactivity of Pd-TiO2
PublikacjaA series of microemulsion (ME) system, constituted by different water to surfactant molar ratios (Wo) and oil to surfactant mass ratios (S), have been applied for Pd-TiO2 preparation. The effect of ME properties on the morphology of Pd nanoparticles formed at TiO2 surface and an effect of Pd size and distribution on the surface and photocatalytic properties of Pd-TiO2 were investigated. Microemulsion systems were characterized...
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Electrical and mechanical properties of nitrided sol-gel derived TiO2 and SiO2-TiO2 films
PublikacjaW pracy opisano właściwości elektryczne i mechaniczne cienkich warstw zawierających TiN. Warstwy tlenkowe TiO2 i TiO2-SiO2 zostały przygotowane metodą zol-żel i następnie poddane procesowi amonolizy. Przewodność elektryczna została zmierzona w zaktesie temperatur 10-900K. Warstwy o dużej zawartości TiN charakteryzują się małą energią aktywacji, poniżej 0,1eV. Badania wykazały dużą twardość próbek o wysokiej zawartości TiN.
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Silver(I) complexes with nitrile ligands: New materials with versatile applications
PublikacjaIn the present study, the structure, thermal stability, conductive properties, and antimicrobial activity of silver(I) complexes with nitrile ligands were investigated. For the construction of the materials, 2-cyanopyridine (2-cpy), 4-cyanopyridine (4-cpy), 1,2-dicyanobenzene (1,2-dcb), and 1,3-dicyanobenzene (1,3-dcb) were used in addition to the silver nitrite and nitrate. Four new compounds were isolated and structurally characterized:...
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Photoluminescence spectra of TiO2
Dane BadawczeThese data contain photoluminescence spectra of TiO2 measured at the temperature of liquid nitrogen. There is a comparison of the photoluminescence spectra of TiO2 heat treated at 400-600oC in the ambient (Ar) and reduced (H2) atmospheres. These emission spectra were recorded after TiO2 excitation with a wavelength of 290 nm
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Crystal facet effects in photocatalytic degradation of organic pollutants over anatase TiO2
PublikacjaPresented work show detailed effect of the exposed crystal facets of anatase TiO2 on the photocatalytic degradation of organic pollutants. The most important existing information about the geometry and electronic properties of the low index anatase facets are summarised. During the performed works, anatase nanoparticles with the dominant exposition of either {0 0 1}, {1 0 0} or {1 0 1} crystal facets were prepared and their photocatalytic...
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Cancer-selective, single agent chemoradiosensitising gold nanoparticles
PublikacjaTwo nanometre gold nanoparticles (AuNPs), bearing sugar moieties and/or thiol-polyethylene glycol-amine (PEG-amine), were synthesised and evaluated for their in vitro toxicity and ability to radiosensitise cells with 220 kV and 6 MV X-rays, using four cell lines representing normal and cancerous skin and breast tissues. Acute 3 h exposure of cells to AuNPs, bearing PEG-amine only or a 50:50 ratio of alpha-galactose derivative and...
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Fotokatalityczne właściwości TiO2
PublikacjaFotokataliza to reakcja zachodząca na skutek absorpcji światła przez fotokatalizator lub substrat. Fotokatalizator to substancja, która wpływa korzystnie na przebieg reakcji zachodzącej pod wpływem światła i sama nie ulega zużyciu. Dobry fotokatalizator powinien wykazywać wysoką aktywność fotokatalityczną. Wśród półprzewodników wykazujących działanie fotokatalityczne w reakcjach degradacji związków organicznych za najbardziej efektywny...
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XRD-TiO2 and SiO2
Dane BadawczeData contain results from XRD measurements of amorphous silica and TiO2 of antase and rutile phases. The commercial TiO2 named as P25 produced by Evonik was also analyzed.
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A spectroscopic study of the cis/trans-isomers of penta-2,4-dienoic acid attached to gold nanoclusters
PublikacjaIn this theoretical work, we present a spectroscopic analysis of the cis/trans-isomers of a molecular switch, penta-2,4-dienoic acid, attached to gold clusters of different size (1, 2 and 20 gold atoms). We have simulated 4 different spectroscopic techniques: Infrared spectroscopy, normal Raman scattering, absorption spectra and resonance Raman scattering. We discuss how the position and the conformation of the molecule determine...
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Photocatalytic activity of TiO2 immobilized on glass beads
PublikacjaAktywność fotokatalityczną czystego TiO2 oraz TiO2 modyfikowanego borem zbadano w reakcji degradacji wodnego roztworu fenolu. TiO2 osadzono na szklanych kulkach i umieszczono w reaktorze wyposażonym w szklaną, kwarcową rurę, którą naświetlano promieniowaniem z zakresu UV-Vus
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Carnivorous plants used for green synthesis of silver nanoparticles with broad-spectrum antimicrobial activity
PublikacjaIn this study, we exploit the anti-oxidative potential of four carnivorous plants to produce uniform and biologically active silver nanoparticles. The use of polyvinylpyrrolidone promoted syn-thesis of quasi-spherical nanoparticles characterized by stability and high uniformity. Their activity was tested against three human pathogens and three species of plant pathogenic bacteria. The study demonstrates the influence of synthesis...
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Anna Zielińska-Jurek prof. dr hab. inż.
OsobyResearch work on photocatalysis by Prof. Anna Zielinska-Jurek started in 2006 at Gdansk University of Technology (Poland), including 3-month research stay at Hokkaido University, Training School “Environmental Applications of TiO2 Photocatalysis” at the University of Oulu in Finland granted by COST Program and Training School “NanoBiophotonics” at the Beckmann Institute, Urbana-Champaign in the USA granted by University of Illinois....
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EXAMINATION OF SOL-GEL DERIVED HYDROXYAPATITE ENHANCED WITH SILVER NANOPARTICLES USING OCT AND RAMAN SPECTROSCOPY
PublikacjaHydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements...
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Photocatalytic activity of boron-modified TiO2 under visible light: The effect of boron content, calcination temperature and TiO2 matrix
PublikacjaPrzedstawiono wpływ temperatury kalcynacji (200, 300, 350, 400, 450 oraz 600oC) na fotoaktywność w świetle widzialnym (l> 400 nm) oraz właściwości powierzchniowe TiO2 modyfikowanego borem. B-TiO2 został przygotowany metodą impregnacji powierzchniowej. Jako prekursor bory wykorzystano ester trietylowy kwasu borowego (BATE). Charakterystyka otrzymywanych fotokatalizatorów obejmowała wyznaczenie powierzchni właściwej, właściwości...
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Reactions of methyl radicals with silica supported silver nanoparticles in aqueous solutions
PublikacjaSilica supported silver nanoparticles (Ag°–SiO2 –NCs, NCs=nanocomposites) suspended in aqueous solutions are efficient catalysts for the dimerization of methyl radicals to produce ethane, while bare silica is quite inert towards the interaction with methyl radicals. In the presence of small amounts of ethanol adsorbed on the SiO2 surface, the reaction path with methyl radicals is changed and methane is formed as the major product.
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In Vitro Biological Characterization of Silver-Doped Anodic Oxide Coating on Titanium
PublikacjaDespite the high biocompatibility and clinical effectiveness of Ti-based implants, surface functionalization (with complex osteointegrative/antibacterial strategies) is still required. To enhance the dental implant surface and to provide additional osteoinductive and antibacterial properties, plasma electrolytic oxidation of a pure Ti was performed using a nitrilotriacetic acid (NTA)-based Ag nanoparticles (AgNP)-loaded calcium–phosphate...
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Spontaneous electron emission vs dissociation in internally hot silver dimer anions
PublikacjaReferring to a recent experiment, we theoretically study the process of a two-channel decay of the diatomic silver anion (Ag2-), namely the spontaneous electron ejection giving Ag2 + e- and the dissociation leading to Ag- + Ag. The ground state potential energy curves of the silver molecules of diatomic neutral and negative ion were calculated using proper pseudo-potentials and atomic basis sets. We also estimated the non-adiabatic...
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Induced-fit binding of laccase to gold and carbon electrodes for the biological fuel cell applications
PublikacjaAnalogues of laccase natural substrates (syringic, veratric, ferulic, vanillic, isovanillic, 3,5-dimethoxybenzoic aldehydes) were employed to bind and orient laccase molecules in a way which facilitates adsorption of the catalyst molecules and their electrical connection with the conductive support. Laccase was bound efficiently to these substrates both on gold and carbon electrodes forming, respectively, 2D and 3D films sensitive...
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Structure of liquid gold from tight-binding driven molecular-dynamics
PublikacjaPraca przedstawia wyniki symulacji ciekłego złota w nadkomórce periodycznej przy użyciu stworzonego przez autorów programu komputerowego, za pomocą połączonych metod dynamiki molekularnej (MD) i ciasnego wiązania (TB). Omówiono strukturę tak symulowanej cieczy, porównując ją z dostępnymi danymi doświadczalnymi oraz wynikami innych symulacji, pod kątem radialnej i kątowej funkcji rozkładu i elektronowej gęstości stanów.A tight-binding...
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Influence of silver nanoparticles addition on antibacterial properties of PEO coatings formed on magnesium
PublikacjaMagnesium is a biodegradable material and thus could be a choice for bone fixation devices and implants with a specific purpose. This study aims to enhance the anti-corrosive, biocompatible, and antibacterial properties on magnesium-based materials through ceramic coatings formation. To achieve this the silicate-based electrolyte was used to create of Plasma Electrolytic Oxidation (PEO) coatings. During investigation the bioactive...
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The share of investments in gold and oil using the example of selected European stock exchanges– A comparative analysis
PublikacjaIn this article, optimal investment portfolios with minimal risk and maximum efficiency were calculated. The portfolios were designated for ten selected European stock exchanges, based on the listings of the twenty largest companies in each of those markets. All calculations were made based on company shares only, company shares and investments in gold, shares of companies and investments in crude oil as well as shares of companies...
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Studies on Silver Ions Releasing Processes and Mechanical Properties of Surface-Modified Titanium Alloy Implants
PublikacjaDispersed silver nanoparticles (AgNPs) on the surface of titanium alloy (Ti6Al4V) and titanium alloy modified by titania nanotube layer (Ti6Al4V/TNT) substrates were produced by the chemical vapor deposition method (CVD) using a novel precursor of the formula [Ag5(O2CC2F5)5(H2O)3]. The structure and volatile properties of this compound were determined using single crystal X-ray diffractometry, variable temperature IR spectrophotometry...
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Progress, Challenge, and Perspective of Bimetallic TiO2-Based Photocatalysts
PublikacjaBimetallic TiO2-based photocatalysts have attracted considerable attention in recent years as a class of highly active catalysts and photocatalysts under both UV and Vis light irradiation. Bimetallic noble metal structures deposited on TiO2 possess the ability to absorb visible light, in a wide wavelength range (broad LSPR peak), and therefore reveal the highest level of activity as a result of utilization of a large amount of...
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TiO2-TG analyses -OH groups
Dane BadawczeTG analyses of TiO2 were performed under nitrogen flow to monitor desorption of hydroxyl groups. Physisorbed weak-bonded hydroxyl groups were desorbed totally at around 120oC, whereas chemisorbed ones at around 500oC. The mass loss at these temperatures was used as concentration of hydroxyl groups on TiO2 surface. The amount of analysed TiO2 was 10...
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ASSESSMENT OF GOLD AND/OR CRUDE OIL AS INVESTMENTS FOR PORTFOLIO DIVERSIFICATION. A WARSAW STOCK EXCHANGE CASE STUDY
PublikacjaThe purpose of the study is to assess whether the inclusion of investments in gold and/or crude oil improves an investment portfolio consisting of shares of enterprises included in the WIG20 index (traditional invest-ments). All possible combinations of investment portfolios with minimal risk and maximum efficiency were tested. The portfolios were determined based on Markowitz’s portfolio theory. All results were compared...
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Photocatalytic activity of TiO2 loaded with metal clusters
PublikacjaTiO2 modyfikowano powierzchniowo klasterami metali: srebra, złota i platyny. Zbadano wpływ rodzaju i ilości wprowadzonej domieszki, oraz matrycy TiO2 na aktywność fotokatalityczną otrzymanych próbek. Fotoaktywność próbek badano w reakcji degradacji fenolu (Co = 0,21 mmol/dm3 ) w zakresie światła Vis lub UV. Najwyższą aktywność zaobserwowano dla fotokatalizatorów zawierających 2%Ag, 1%Au oraz 0,5%Pt. Po 60 min naświetlania światłem...
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Effects Induced by the Temperature and Chemical Environment on the Fluorescence of Water-Soluble Gold Nanoparticles Functionalized with a Perylene-Derivative Dye
PublikacjaWe developed a fluorescent molecular probe based on gold nanoparticles functionalized with N,N′-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylenetetracarboxylic acid diimide dihydrochloride, and these probes exhibit potential for applications in microscopic thermometry. The intensity of fluorescence was affected by changes in temperature. Chemical environments, such as different buffers with the same pH, also resulted in different fluorescence...
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Morphology of the gold nanoislands
Dane BadawczeDewetting of the thin metallic films leads to formation of an isolated islands. morphology of nanostructures was measured by SEM microscope. Thin gold films with a thickness of 1.2 nm, 1.5 nm and 3.4 nm were anealed at 550, 600 and 650 Celcius degress.
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TiO2-zeta potential
Dane BadawczeData contain results from the measurements of zeta potential of TiO2 versus pH. Data are saved as original files and in the format of Excel file. measurements were perfomed in Zetasizer Nano ZS with using Multi-Purpose Titrator MPT-2.
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Preparation of silver nanoparticles in reverse micelles and antibacterial activity of silver modified-paints
PublikacjaW publikacji została opisana metoda otrzymywania nanocząstek srebra oraz farb modyfikowanych srebrem i ich wpływ na zahamowanie rozwoju wybranych bakterii i grzybów. Podjęto również próbę porównania wpływu rodzaju prekursora srebra oraz substancji powierzchniowo czynnej na stabilność otrzymanych nanocząstek srebra. Przygotowane mikroemulsje zawierały od 500 do 2000 ppm srebra
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Hybrid TiO2–Polyaniline Photocatalysts and their Application in Building Gypsum Plasters
PublikacjaHybrid materials of conjugated polymer and titanium(IV) oxide have attracted considerable attention concerning their potential benefits, including (i) ecient exploitation of visible light, (ii) a high adsorption capacity for organic contaminants, (iii) and eective charge carriers separation. The new class of the photocatalysts is promising for the removal of environmental pollutants in both aqueous and gaseous phases. For the first...
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Pr-doped TiO2: The effect of metal content on photocatalytic activity
PublikacjaThe Pr-TiO2 nanoparticles were prepared by using the sol-gel method. As-prepared samples were characterized by BET measurements, X-ray powder diffraction analysis (XRD) and UV-Vis spectra. Visible and ultraviolet light photocatalytic activity of the sample was studied by photodegradation of phenol while considering the influence of the dopant concentration. TiO2 doped with 0.25 mol% of praseodymium showed the highest photocatalytic...
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Integrated Experimental and Theoretical Approach for Efficient Design and Synthesis of Gold-Based Double Halide Perovskites
PublikacjaApplied cutting-edge electronic structure and phonon simulations provide a reliable knowledge about the stability of perovskite structures and their electronic properties, which are crucial for design of effective nanomaterials. Gold is one of the exceptional elements, which can exist both as a monovalent and a trivalent ion in the B site of a double perovskite such as A2BI BIIIX6. However, until now, electronic properties of Cs2AuI AuIIIX6...
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Gold(III) complexes with chloride and cyanopyridines: Facilitated hydrolysis of nitrile ligand to amide and antibacterial activity
PublikacjaA range of novel simple gold(III) compounds has been synthesized in their monocrystalline form, including two previously unknown chloro-complexes of Au3+ with 2-cyanopyridine or 3-cyanopyridine, respectively. Our investigations have revealed the intricate nature of the reaction between 2-cyanopyridine and tetrachloroauric acid, yielding at least three distinct products. The main product, obtained in high yield, is a salt featuring...
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Analyses of sulphur in TiO2 by XRFS
Dane BadawczeData contain content of sulphur in TiO2 determined by X-ray fluorescence spectroscopy. The results were obtained by using internal pattern.
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Methane formation over TiO2–based photocatalysts: reaction pathways
PublikacjaThe effects of organic impurities adsorbed or incorporated into semiconductors structure on the photocatalytic products are noteworthy. For this purpose, the as-prepared Ag, Au and Pdmodified TiO2 samples were exposed to UV-vis irradiation in various gas atmospheres (CO2, N2, 600 ppm CO2 in N2, and 13CO2) in order to clarify the route of CH4 formation in the process of photocatalytic CO2 reduction. In the presented research it...
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Fluctuation-Enhanced Sensing with Organically Functionalized Gold Nanoparticle Gas Sensors Targeting Biomedical Applications
PublikacjaDetection of volatile organic compounds is a useful approach to non-invasive diagnosis of diseases through breath analysis. Our experimental study presents a newly developed prototype gas sensor, based on organically-functionalized gold nanoparticles, and results on formaldehyde detection using fluctuation-enhanced gas sensing. Formaldehyde was easily detected via intense fluctuations of the gas sensor’s resistance, while the cross-influence...
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Photocatalytic decomposition of acetaldehyde over TiO2 (titanium dioxide) supported on nickel foam and Ni-doped (nickel-doped) TiO2
Dane BadawczeThis dataset contains chromatograms recorded during the decomposition of acetaldehyde in a high-temperature reaction chamber under UV irradiation using as photocatalytic systems TiO2 (titanium dioxide) supported on nickel foam, TiO2 supported on oxidized nickel foam and TiO2 doped by metallic nickel (Ni) powder. The detailed equipment and measurement...
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The photoconductivity of sol-gel derived TiO2 films.
PublikacjaPrzygotowano metodą zol-żel warstwy TiO2 na podłożu kwarcowym. Zbadano ich fotoprzewodnictwo w różnych warunkach. Stwierdzono, że fotoprąd w próżni jest o trzy rzędy większy niż w powietrzu. Jako wyjaśnienie zaproponowano absorpcję tlenu na powierzchni warstwy.
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Photo-oxidation of dissolved cyanide using TiO2 catalyst
PublikacjaZbadano utlenianie katalityczne jonów cyjankowych w układzie UV/TiO2. Szybkość utleniania zbadano dla różnego stężenia początkowego CN-, wartość pH, formy katalizatora, temperatury oraz wprowadzanej formy gazowej. Stwierdzono że szybkość degradacji cyjanków w układzie UV/TiO2/O2 wzrasta dwukrotnie, jakkolwiek jest niezależna od ciśnienia cząstkowego tlenu (0,2-1,0 atm.). Wzrost temperatury środowiska reakcji w zakresie od 20 do...
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TiO2-potential zeta in water
Dane BadawczeData contain results from measurements of zeta potential for powdered TiO2 in a diluted aqueous solution. The measurements were performed in Zetasizer Nano ZS analyser.
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Photocatalytic decomposition of ethylene on the TiO2-polystyrene spheres
Dane BadawczeData contain results from the measurements of the photocatalytic decomposition of ethylene under UV irradiation with using TiO2 coating on the expanded polystyrene spheres (EPS). EPS-SiO2-TiO2 and EPS-TiO2 were used as the photocatalytic beds in the fluidized bed reactor. Both, stationary and fluidized beds were tested. The comparison of ethylene decomposition...
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Enhanced photocatalytic activity of transparent carbon nanowall/TiO2 heterostructures
PublikacjaThe synthesis of novel tunable carbon-based nanostructure represented a pivotal point to enhance the efficiency of existing photocatalysts and to extend their applicability to a wider number of sustainable processes. In this letter, we describe a transparent photocatalytic heterostructure by growing boron-doped carbon nanowalls (B-CNWs) on quartz, followed by a simple TiO2 sol-gel deposition. The effect on the thickness and boron-doping...
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Comprehensive study on graphene hydrogels and aerogels synthesis and their ability of gold nanoparticles adsorption
PublikacjaGraphene hydrogels were prepared by ascorbic acid-assisted gelation of graphene oxide (GO) aqueous suspensions both in acidic and basic conditions. Different mass ratio of ascorbic acid (AA) to GO was used (namely 20:1 and 10:1). In order to eliminate the influence of AA on the final structure of hydrogels, samples without AA were prepared by a hydrothermal gelation of GO in an autoclave. An in-depth structural characterization...
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TiO2-based magnetic nanocomposites with core-shell structure
PublikacjaThe main aim of the doctoral dissertation was preparation and characterization of photocatalysts, with particular emphasis on modified titanium (IV) oxide photocatalysts, which can be applied for the degradation of organic pollutants not susceptible to biodegradation. A particularly important aspect of the work was the development of preparation method of nanocomposites with the magnetic core-shell and photocatalyst shell (TiO2)...