Nanocrystalline TiO2 studied by optical, FTIR and X-ray photoelectron spectroscopy: correlation to presence of surface states

Kumar, P. Pradeep; Badrinarayanan, S.; Sastry, Murali

doi:10.1016/s0040-6090(99)00722-1

Cited by 685 publications

(399 citation statements)

References 35 publications

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“…This region at 3600 -3800 cm Ϫ1 was therefore identified as being representative of nonhydrogen-bonded hydroxyl groups (labeled as isolated or free hydroxyl groups). This is in agreement with the X-ray data analysis of Kumar et al 30 and will be further discussed below.…”

Section: Infrared Spectroscopysupporting

confidence: 91%

“…5(A)] is similar to that obtained by Wu (i.e., ref. 20 The new peak at 18.3°, which may be due to the formation of an ester carbonyl functional group as described in the discussion of FTIR analysis, was also reported by Shogren et al 37 Also, one can refer the appearance of the new peaks at 2 ϭ 26.1°and 29.1°to the generation of a titanium-bonded isopropyl functional group in the anatase and rutile phase, 30 and the appearance of the new peak at 2 ϭ 22.7°to the generation of a titania functional group in the Ti 2 O 3 phase.…”

Section: X-ray Diffractionmentioning

confidence: 54%

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In situ polymerization of titanium isopropoxide in polycaprolactone: Properties and characterization of the hybrid nanocomposites

2004

J of Applied Polymer Sci

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ABSTRACT:In this study, tetra isopropyl ortho titanate (TTIP) and polycaprolactone (PCL) were chosen as the ceramic precursor and the continuous phase, respectively, for the preparation of novel nanocomposites by using an in situ sol-gel process. In addition, acrylic acid grafted polycaprolactone (PCL-g-AA) was investigated as an alternative to PCL. The hybrids (PCL/TiO 2 and PCL-g-AA/TiO 2 ) were characterized via Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical thermal analysis (DMA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and Instron mechanical testing. It was found that the carboxylic acid groups of acrylic acid acted as coordination sites for the titania phase to form chemical bonds, thus improving the properties of the acrylic acid grafted composite compared with its acrylicacid-free counterpart. The TiO 2 content also determined the strength of interfacial bonding between the polymer chains and the ceramic phase, as shown by changes in glass transition temperature (T g ) with TiO 2 content. The maximum values of tensile strength and T g were obtained with the PCL-g-AA/TiO 2 composite at 10 wt % TiO 2 . At TiO 2 contents above this, excess particles led to segregation between the organic and inorganic phases.

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Section: Infrared Spectroscopysupporting

confidence: 91%

Section: X-ray Diffractionmentioning

confidence: 54%

In situ polymerization of titanium isopropoxide in polycaprolactone: Properties and characterization of the hybrid nanocomposites

2004

J of Applied Polymer Sci

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“…46,49 Second, the observed slight shift in the 500 cm −1 band toward a smaller wavenumber in sample l is also related to changes in particle size effect. 39,46 Finally, we remark that the cleanliness of deposition method and analysis conditions are confirmed by the absence of bands associated with OH and uCH, uCH 2 groups in the 3200-3800 cm −1 , 2500-3600 cm −1 , and 1400-2900 cm −1 regions ͑not shown͒, respectively. 49 XRD experiments probe deeper parts of the samples than XPS measurements.…”

Section: B Structure Dependence On the Materials Compositionmentioning

confidence: 55%

“…For curves k to q there is a unique symmetric band centered at ϳ530.6 eV corresponding to O 2− in Ti 4+ u O bonds. 39 In the other hand, at lower P O 2 values, this band becomes broader, asymmetric, and a shoulder at lower energies is defined. These features are characteristic of different oxygen bonds and can be identified using the same fitting procedure employed above.…”

Section: Results: Analysis Of the Experimental Datamentioning

confidence: 96%

A comprehensive study of the influence of the stoichiometry on the physical properties of TiOx films prepared by ion beam deposition

Marchi

Bilmes

Ribeiro³

et al. 2010

Journal of Applied Physics

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Articles you may be interested inA comprehensive study of nonstoichiometry titanium oxide thin films ͑TiO x , 0.3Յ x Յ 2͒ prepared by ion beam deposition technique is reported. The physical properties of the material are studied by ultraviolet and x-ray photoelectron, Raman, and Fourier transform infrared spectroscopies, and atomic force microscopy. An abrupt transition from metallic characteristics to a wide gap semiconductor is observed in a very narrow range of oxygen variation. Concomitantly with this change the crystal structure and morphology suffer remarkable physical properties modifications. This transformation is ascribed to surface-volume energy minimization due to the influence of oxygen determining the size of the TiO 2 particles during coalescence.

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“…photoelectrical devices, solid state lasers, flat panel displays, detectors of high energy radi-ation, optical data storage devices, or even medical diagnostic equipment [1][2][3][4][5]. For such applications lanthanides were incorporated into different types of materials, which had crystalline structure or were amorphous.…”

Section: Introductionmentioning

confidence: 99%

Influence of terbium on structure and luminescence of nanocrystalline TiO2 thin films

et al. 2013

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Abstract:In this work analysis of the structural and optical properties of TiO 2 thin films doped with terbium has been described. Samples were prepared by a high energy reactive magnetron sputtering process under low pressure of oxygen plasma. X-ray diffraction results have shown that different TiO 2 crystal forms have been produced, depending on the amount of Tb dopant. The undoped matrix had rutile structure with crystallites with a size of 8.7 nm, while incorporation of 0.4 at. % of Tb into the film during the sputtering process resulted in anatase structure with bigger crystallites (11.7 nm). Increasing the amount of terbium up to 2 at. % and 2.6 at. % gave rutile structure with crystallites with a size of 6.6 nm for both films. However, Raman spectroscopy has revealed that in the case of TiO 2 :(2 at. % Tb), except for the rutile form, the presence of fine-crystalline anatase was observed. Moreover, the lack of Raman peaks shift attests to the lack of stress in the titania lattice of all of the TiO 2 :Tb films. This fact indicates localization of Tb 3+ ions on the surface of TiO 2 nanocrystals. In the case of optical investigation, results have shown that doping with terbium has a significant influence on the properties of TiO 2 , but it does not decrease the high transparency of the matrix. The observed changes of the transmission characteristics were produced only due to modification of the TiO 2 :Tb structure. Photoluminescence measurements have shown that emission of light from TiO 2 :Tb films occurs when the amount of terbium is 2.6 at. %. Based on the obtained results a scheme of direct energy transfer from titanium dioxide matrix (with rutile structure) to Tb 3+ ions has been proposed.

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Nanocrystalline TiO2 studied by optical, FTIR and X-ray photoelectron spectroscopy: correlation to presence of surface states

Cited by 685 publications

References 35 publications

In situ polymerization of titanium isopropoxide in polycaprolactone: Properties and characterization of the hybrid nanocomposites

In situ polymerization of titanium isopropoxide in polycaprolactone: Properties and characterization of the hybrid nanocomposites

A comprehensive study of the influence of the stoichiometry on the physical properties of TiOx films prepared by ion beam deposition

Influence of terbium on structure and luminescence of nanocrystalline TiO2 thin films

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