The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Panagiotis G Smirniotis - One of the best experts on this subject based on the ideXlab platform.
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novel one step synthesis of Nitrogen doped tio2 by flame aerosol technique for visible light photocatalysis effect of synthesis parameters and secondary Nitrogen n source
Chemical Engineering Journal, 2018Co-Authors: Thirupathi Boningari, Siva Nagi Reddy Inturi, Makram T Suidan, Panagiotis G SmirniotisAbstract:Abstract For the first time, Nitrogen-doped TiO2 was successfully synthesized by a novel single-step flame spray pyrolysis (FSP) method. Our X-ray photoelectron spectroscopy results illustrate that the Nitrogen was effectively doped into the crystal structure of TiO2 in our as-synthesized N-TiO2 catalysts predominantly in the form of interstitial Nitrogen (Ti–O−N) rather than substitutional Nitrogen (Ti–N). The shift of the (1 0 1) plane anatase diffraction peaks to lower angles in our N-doped TiO2 catalysts compared to pristine TiO2 revealed the distortion and strain in the crystal structure instigated by the incorporation of the Nitrogen Atoms. The growth or expansion of crystal lattice can be attributed to the larger atomic radius of respective Nitrogen Atoms (r = 1.71 A) compared to oxygen (r = 1.40 A). Our single-step rapid aerosol synthesis method directs the Nitrogen Atoms mainly occupy interstitial positions in TiO2 lattice. The increase in the primary Nitrogen content does not impact the bandgap energies (from 2.54 eV to 2.53 eV), whereas increase in the secondary source monotonically decreased (from 2.95 eV to 2.47 eV) the bandgap energies. This observed lowering of the band-gap energy for the flame made N-doped TiO2 materials implies that the Nitrogen doping in TiO2 by aerosol method is highly effective in extending the optical response of TiO2 in the visible region. The Nitrogen Atoms incorporation into the crystal structure of titania alters the electronic band structure of TiO2, resulting to a new mid-gap energy state N 2p band formed above O 2p valance band. This occurrence narrows the band gap of TiO2 (from 3.07 to ∼2.47 eV) in our N-doped TiO2 and shifts the optical absorption to the visible region.
Aleksandar Matic - One of the best experts on this subject based on the ideXlab platform.
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structure of glassy lithium sulfate films sputtered in Nitrogen insight from raman spectroscopy and ab initio calculations
Physical Review B, 2008Co-Authors: Christian R Muller, Patrik Johansson, Maths Karlsson, Philipp Maass, Aleksandar MaticAbstract:Raman spectra of thin solid electrolyte films obtained by sputtering a ${\mathrm{Li}}_{2}\mathrm{S}{\mathrm{O}}_{4}$ target in Nitrogen plasma are measured and compared to ab initio electronic structure calculations for clusters composed of 28 Atoms. Agreement between measured and calculated spectra is obtained only when some oxygen Atoms are replaced by Nitrogen Atoms and when these Nitrogen Atoms form bonds with each other. This suggests that the incorporation of Nitrogen during the sputtering process leads to structures in the film, which prevent crystallization of these thin film salt glasses.
Linjie Fan - One of the best experts on this subject based on the ideXlab platform.
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effect of the Nitrogen oxygen ratio on the position of n Atoms in the tio2 lattice of n doped tio2 thin films prepared by dc magnetron sputtering
CrystEngComm, 2018Co-Authors: Dingyu Yang, Xinghua Zhu, Hui Sun, Peihua Wangyang, Linjie FanAbstract:The Nitrogen-doped TiO2 thin films are deposited on the glass substrate by using a direct-current (DC) magnetron sputtering technique. The film properties are analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) measurements. The results show that, under the same working pressure and other conditions, Nitrogen doping promotes the phase transition from anatase to rutile. Also, on changing the Nitrogen–oxygen ratio, Nitrogen Atoms enter the TiO2 lattice in different positions. When oxygen is abundant, Nitrogen Atoms will be presented in the interstitial positions; when oxygen is insufficient, Nitrogen Atoms enter the oxygen vacancies first, forming a substituted position. Finally, we find that, with the increase in Nitrogen–oxygen ratio, the sample has a better response to visible light, attributed to the change in the energy band-gap.
Xinghua Zhu - One of the best experts on this subject based on the ideXlab platform.
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effect of the Nitrogen oxygen ratio on the position of n Atoms in the tio2 lattice of n doped tio2 thin films prepared by dc magnetron sputtering
CrystEngComm, 2018Co-Authors: Dingyu Yang, Xinghua Zhu, Hui Sun, Peihua Wangyang, Linjie FanAbstract:The Nitrogen-doped TiO2 thin films are deposited on the glass substrate by using a direct-current (DC) magnetron sputtering technique. The film properties are analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) measurements. The results show that, under the same working pressure and other conditions, Nitrogen doping promotes the phase transition from anatase to rutile. Also, on changing the Nitrogen–oxygen ratio, Nitrogen Atoms enter the TiO2 lattice in different positions. When oxygen is abundant, Nitrogen Atoms will be presented in the interstitial positions; when oxygen is insufficient, Nitrogen Atoms enter the oxygen vacancies first, forming a substituted position. Finally, we find that, with the increase in Nitrogen–oxygen ratio, the sample has a better response to visible light, attributed to the change in the energy band-gap.
Thirupathi Boningari - One of the best experts on this subject based on the ideXlab platform.
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novel one step synthesis of Nitrogen doped tio2 by flame aerosol technique for visible light photocatalysis effect of synthesis parameters and secondary Nitrogen n source
Chemical Engineering Journal, 2018Co-Authors: Thirupathi Boningari, Siva Nagi Reddy Inturi, Makram T Suidan, Panagiotis G SmirniotisAbstract:Abstract For the first time, Nitrogen-doped TiO2 was successfully synthesized by a novel single-step flame spray pyrolysis (FSP) method. Our X-ray photoelectron spectroscopy results illustrate that the Nitrogen was effectively doped into the crystal structure of TiO2 in our as-synthesized N-TiO2 catalysts predominantly in the form of interstitial Nitrogen (Ti–O−N) rather than substitutional Nitrogen (Ti–N). The shift of the (1 0 1) plane anatase diffraction peaks to lower angles in our N-doped TiO2 catalysts compared to pristine TiO2 revealed the distortion and strain in the crystal structure instigated by the incorporation of the Nitrogen Atoms. The growth or expansion of crystal lattice can be attributed to the larger atomic radius of respective Nitrogen Atoms (r = 1.71 A) compared to oxygen (r = 1.40 A). Our single-step rapid aerosol synthesis method directs the Nitrogen Atoms mainly occupy interstitial positions in TiO2 lattice. The increase in the primary Nitrogen content does not impact the bandgap energies (from 2.54 eV to 2.53 eV), whereas increase in the secondary source monotonically decreased (from 2.95 eV to 2.47 eV) the bandgap energies. This observed lowering of the band-gap energy for the flame made N-doped TiO2 materials implies that the Nitrogen doping in TiO2 by aerosol method is highly effective in extending the optical response of TiO2 in the visible region. The Nitrogen Atoms incorporation into the crystal structure of titania alters the electronic band structure of TiO2, resulting to a new mid-gap energy state N 2p band formed above O 2p valance band. This occurrence narrows the band gap of TiO2 (from 3.07 to ∼2.47 eV) in our N-doped TiO2 and shifts the optical absorption to the visible region.
