Determination of band gaps of self-assembled carbon nanotube films using Tauc/Davis–Mott model

Li, Xinming; Zhu, Hongwei; Wei, Jinquan; Wang, Kunlin; Xu, Eryang; Li, Zhen; Wu, Dehai

doi:10.1007/s00339-009-5330-z

Cited by 97 publications

(54 citation statements)

References 25 publications

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“…This might be due to the interaction of the -OH group in CTS with Ti 4+ . 27 The values of E g for Ti-CTS and Ti-CTS-Cr composites were 0.586 eV and 0.577 eV (n ¼ 2), respectively. In addition, the broad bands at 900-400 cm À1 were revealed for the Ti-O vibration and Ti Lewis sites, interacting with NH 2 groups from the chitosan chain.…”

Section: Adsorption Of Chromium On the Ti-cts Compositementioning

confidence: 94%

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

et al. 2015

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For the simultaneous adsorption and detoxification of hexavalent chromium from water, a new titaniumchitosan (Ti-CTS) composite was synthesized through a metal-binding reaction between titanium ions and the chitosan biopolymer followed by cross-linking with glutaraldehyde. The resultant composite was characterized by FT-IR, XRD, elemental mapping, SEM and XPS. The adsorption properties toward Cr(VI) were systematically investigated as a function of pH, dosage, initial concentration, contact time, temperature and co-existing ions. Experimental data were well described by the Langmuir isotherm and the pseudo-second order model with the maximum adsorption capacity of 171 mg g À1 . More attractively, the Cr(VI) could be effectively adsorbed and reduced to the less toxic Cr(III) by the Ti-CTS composite.The experimental results, FT-IR and XPS indicated that the possible removal mechanism of Cr(VI) onto the Ti-CTS composite was summarized into three steps: (i) Cr(VI) adsorption by electrostatic attraction (Ti 4+ and HCrO 4 À ) and ligand exchange (Cl À and HCrO 4 À ); (ii) Cr(VI) partly reduced to Cr(III); (iii) the re-adsorption of Cr(III) onto the Ti-CTS composite. Fig. 2 The wide scan XPS spectra of the Ti-CTS composite without (A) and with (B) Cr(VI) adsorbed; high resolution Cr 2p spectra of the Ti-CTS-Cr composite before (C) and after (D) desorption with NaOH. J. Mater. Chem. AThis journal is

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Section: Adsorption Of Chromium On the Ti-cts Compositementioning

confidence: 94%

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

et al. 2015

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“…[47][48][49]73 Our assumption is that soot particles are comprised of condensed aromatic systems of high symmetry and it is reasonable to assume that the transitions are quantum mechanically allowed. 40,41,77 In this data set, the tomographically reconstructed data was plotted by a manipulated eqn (1), where (aÁhn) 1/r was plotted as a function of photon energy (eV), converted from wavelength. Seo and Hoffmann describe the complicated nature of predicting the type of band gap transition in stacked conjugated systems based on the overlapping carbon sites.…”

Section: Obg Calculationmentioning

confidence: 99%

“…38,40,41,77 In any case, the selection of the spectral range used in the Tauc/Davis-Mott analysis is important because the interpolated OBG will be highly dependent on this selection. If this portion of the extinction curve is included, the OBG will be lowered.…”

Section: Obg Calculationmentioning

confidence: 99%

Extinction measurements for optical band gap determination of soot in a series of nitrogen-diluted ethylene/air non-premixed flames

Adkins

Miller

2015

Phys. Chem. Chem. Phys.

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Visible light extinction was measured in a series of nitrogen-diluted, ethylene/air, non-premixed flames and this data was used to determine the optical band gap, OBG, as a function of flame position. Collimated light from a supercontinuum source is telescopically expanded and refocused to match the f- number of a dispersing monochromator. The dispersed light is split into a power metering channel and a channel that is periscoped and focused into the flame. The transmitted light is then recollimated and focussed onto a silicon photodiode detector. After tomographic reconstruction of the radial extinction field, the OBG was derived from the near-edge absorption feature using Tauc/Davis-Mott analysis. A slight evolution in OBG was observed throughout all flame systems with a consistent range of OBG observed between approximately 1.85 eV and 2.35 eV. Averaging over all positions the mean OBG was approximately 2.09 eV for all flame systems. Comparing these results to previously published computational results relating calculated HOMO-LUMO gaps for a variety of D2h PAH molecules to the number of aromatic rings in the structure, showed that the observed optical band gap is consistent with a PAH of about 14 rings or a conjugation length of 0.97 nm. This work provides experimental support to the model of soot formation where the transition from chemical to physical growth starts at a modest molecular size; about the size of circumpyrene.

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“…At a high temperature of 450 C, Te powders are vaporized to form the gaseous Te molecules, which subsequently react with oxygen in air to form the gaseous TeO 2 molecules. 27 The estimated band gap is 3.68 eV, which is slightly lower than the conventional 3.8 eV. To minimize the surface energy, the gaseous TeO 2 molecules facilitate directional growth.…”

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confidence: 94%

A low-temperature n-propanol gas sensor based on TeO₂ nanowires as the sensing layer

et al. 2015

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TeO 2 nanowires were synthesized on Au-coated glass substrates using a thermal evaporation method. Structural characterization showed that TeO 2 nanowires with high surface-to-volume ratio and large mass production had a single-crystal tetragonal structure. A gas sensor based on TeO 2 nanowires showed a quick response-recovery speed and a reversible response to n-propanol gas at low operating temperatures.

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Determination of band gaps of self-assembled carbon nanotube films using Tauc/Davis–Mott model

Cited by 97 publications

References 25 publications

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

Extinction measurements for optical band gap determination of soot in a series of nitrogen-diluted ethylene/air non-premixed flames

A low-temperature n-propanol gas sensor based on TeO₂ nanowires as the sensing layer

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Determination of band gaps of self-assembled carbon nanotube films using Tauc/Davis–Mott model

Cited by 97 publications

References 25 publications

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

Synthesis of titanium cross-linked chitosan composite for efficient adsorption and detoxification of hexavalent chromium from water

Extinction measurements for optical band gap determination of soot in a series of nitrogen-diluted ethylene/air non-premixed flames

A low-temperature n-propanol gas sensor based on TeO2 nanowires as the sensing layer

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Product

Resources

About

A low-temperature n-propanol gas sensor based on TeO₂ nanowires as the sensing layer