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1

Electrochemical sensors based on TiO2–Fe2O3 coupled system

Kusior Anna, Karoń Iwona, Radecka Marta

Metrology and Measurement Systems

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2020

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Vol. 27, nr 2

301--311

EN

Recently, transition metal oxides, which exhibit favorable catalytic abilities, have also been investigated as a material for the detection of hydrazine (N2H4). It has been reported that mixed metal oxides usually offer a higher electrochemical activity than binary oxides. In this work, a TiO2-Fe2O3 coupled system is presented as an enhanced material with major applications in electrochemical detectors. The electrochemical behavior of glassy carbon electrodes modified with TiO2-Fe2O3 in the absence and presence of hydrazine was evaluated via cyclic voltammetry (CV). Experimental results also suggest that the formation of the TiO2-Fe2O3 coupled system enhances electrochemical catalytic performance in N2H4 detection. The modificationTiO2+2 mol% Fe2O3 provides good analytical performance of detection (0.13 mM) and quantification limits (0.39 mM). The presented coupled system provides the premise for a suitable material for a stable and sensitive N2H4 sensor.

2

Właściwości strukturalne, optyczne i elektryczne TiO2 modyfikowanego Fe2O3

Karoń Iwona, Radecka Marta

Materiały Ceramiczne

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2019

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T. 71, nr 1

17--24

PL

Celem pracy było określenie własności strukturalnych, elektrycznych i optycznych TiO2 modyfikowanego Fe2O3. Materiały TiO2-Fe2O3 syntezowano metodą zol-żel w zakresie (0-2)% mol. Fe2O3. Badania dyfrakcji promieniowania rentgenowskiego XRD wskazują, że niedomieszkowany TiO2 oraz materiały o zawartości do 0,25% mol. Fe2O3 krystalizują w strukturze rutylu. Przewodnictwo elektryczne mierzono w funkcji składu oraz temperatury (425-700 °C). Położenie i kształt krawędzi absorpcji podstawowej zależy od koncentracji domieszki. Własności strukturalne i elektryczne materiałów potwierdzają zakres tworzenia roztworów stałych.

EN

The aim of this work was to determine the structural, electrical and optical properties of the TiO2 modified with Fe2O3. Fe2O3-TiO2 materials were synthetized by the sol-gel method in the range 0-2 mol% Fe2O3. XRD X-ray diffraction studies indicate that undoped TiO2 and materials with a content of up to 0.25 mol% Fe2O3 crystallize in the rutile structure. Electrical conductivity was measured as a function of composition and temperature (425-700 °C). The location and shape of the primary absorption edge depends on the concentration of the admixture. Structural and electrical properties of materials confirm the range of solid solution formation.

3

Structural and Optical Properties of Fe2O3 - NiO mixed Thin Films Prepared by Chemical Spray Pyrolysis

Mohmmed N. J., Habubi M. N.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 14, iss. 1

65--85

EN

Mixed Fe2O3 - NiO thin films have been prepared by chemical Spray pyrolysis technique onto glass substrate preheated to 450 °C. The thickness of thin films was found to be (400 ±20) nm. XRD measurements reveal that all the film exhibit polycrystalline hexagonal wrutzite with a preferred orientation along (104) plane for pure and 10 % and 20 % Ni, while for the rest the structure was amorphous. AFM analysis indicate a nanostructure for all the films. The optical energy gap was found to be increased from optical transitions seems to be direct and the optical energy gap seems to be increased from 2.5 to 2.69 eV as the percentage of NiO increase.

4

An XPS study of RF sputtered Ti1-x FexO2-delta thin films

Dumitru L., Apetrei R., Dobromir M., Dascaleanu V., Teodorescu C M.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 4

15-17

EN

Introduction of small amounts of dopant Fe cations intitania was mainly intended for improving the oxidativepower of the host TiO2 surface, by shifting the absorption edge of the material towards the blue side of the visible range. Apart from this, other possible applications of Fe-containing TiO2 materials have been foreseen in the field of diluted ferromagnetic semiconductors for spintronics. As a general remark, while pristine and/or low-level doped titania materials remained a hot subject in basic research, and environment- and energy related applications, reports on Ti1-x FexO2 materials (x > 0.1) scarcely occurred in literature. We have initiated recently an investigation of heavily doped titania thin films within a wider iron compositionrange. Here, we report on the result of an XPS study of the RF sputtered oxygen-deficient thin films (x =0.15 - 0.62) and discuss the connection of the results with the macroscopic properties of the materials.

5

Oznaczanie AI2O3 i Fe2O3 w boksytach

Stec K., Burdyl M.

Materiały Ceramiczne

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2006

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R. 58, nr 2

68-70

PL

Oznaczanie zawartości tlenku glinu i żelaza w boksytach nie można zaliczyć do rutynowych analiz chemicznych próbek wysokoglinowych. Proponowane metody miareczkowe w normach PN-85/H-04154 i PN-EN 995-2 nie gwarantują uzyskania powtarzalnych wyników oznaczania AI2O3 i Fe2O3. Autorzy przypuszczają, że jest to związane z formą występowania tlenku tytanu w boksytach. Dlatego autorzy pracy podjęli próbę opracowania metodyki pomiaru AI2O3 i Fe2O3 w boksytach gwarantującej powtarzalne wyniki.

EN

Determining chemical composition of bauxite specially AI2O3 and Fe2O3 is not a routine procedure. The titration method proposed in PN-85/H-04154 and PN-EN 995-2 does not guarantee repeatable results of AI2O3 and Fe2O3 determination. It is connected with high concentration of titanium in bauxite. That is why the authors started to develop the new methodology of the AI2O3 and Fe2O3 determination in bauxite which guaranteeing high reproducible and repeatable results.