Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles

Dalaver H. Anjum, Nasir K. Memon, Mohamed Ismail, Mohamed N. Hedhili, Usman Sharif, Suk Ho Chung

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We present a study on the properties of iron (Fe)-doped and carbon (C)-coated titania (TiO2) nanoparticles (NPs) which has been compiled by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). These TiO2 NPs were prepared by using the flame synthesis method. This method allows the simultaneous C coating and Fe doping of TiO2 NPs. XRD investigations revealed that the phase of the prepared NPs was anatase TiO2. Conventional TEM analysis showed that the average size of the TiO2 NPs was about 65 nm and that the NPs were uniformly coated with the element C. Furthermore, from the x-ray energy dispersive spectrometry analysis, it was found that about 8 at.% Fe was present in the synthesized samples. High-resolution TEM (HRTEM) revealed the graphitized carbon structure of the layer surrounding the prepared TiO2 NPs. HRTEM analysis further revealed that the NPs possessed the crystalline structure of anatase titania. Energy-filtered TEM (EFTEM) analysis showed the C coating and Fe doping of the NPs. The ratio of L3 and L2 peaks for the Ti-L23 and Fe-L23 edges present in the core loss electron energy loss spectroscopy (EELS) revealed a +4 oxidation state for the Ti and a +3 oxidation state for the Fe. These EELS results were further confirmed with XPS analysis. The electronic properties of the samples were investigated by applying Kramers-Kronig analysis to the low-loss EELS spectra acquired from the prepared NPs. The presented results showed that the band gap energy of the TiO2 NPs decreased from an original value of 3.2 eV to about 2.2 eV, which is quite close to the ideal band gap energy of 1.65 eV for photocatalysis semiconductors. The observed decrease in band gap energy of the TiO2 NPs was attributed to the presence of Fe atoms at the lattice sites of the anatase TiO2 lattice. In short, C-coated and Fe-doped TiO2 NPs were synthesized with a rather cost-effective and comparatively easily scalable method. The presented analysis enables us to predict the excellent efficiency of these NPs for solar-cell and photo-catalysis applications.

Original languageEnglish
Article number365709
JournalNanotechnology
Volume27
Issue number36
DOIs
Publication statusPublished - 2 Aug 2016
Externally publishedYes

Fingerprint

Transmission Electron Microscopy
Nanoparticles
Carbon
Iron
Titanium
Transmission electron microscopy
Electron Energy-Loss Spectroscopy
X-Rays
Electron energy loss spectroscopy
X rays
Titanium dioxide
Photoelectron Spectroscopy
Energy gap
Photocatalysis
Photoelectron spectroscopy
titanium dioxide
Energy-Filtering Transmission Electron Microscopy
Flame synthesis
Diffraction
Doping (additives)

Keywords

  • flame synthesis of nanoparticles
  • KramersKronig analysis
  • optical properties using EELS
  • transmission electron microscopy
  • x-ray photoelectron microscopy

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

Cite this

Anjum, D. H., Memon, N. K., Ismail, M., Hedhili, M. N., Sharif, U., & Chung, S. H. (2016). Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles. Nanotechnology, 27(36), [365709]. https://doi.org/10.1088/0957-4484/27/36/365709

Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles. / Anjum, Dalaver H.; Memon, Nasir K.; Ismail, Mohamed; Hedhili, Mohamed N.; Sharif, Usman; Chung, Suk Ho.

In: Nanotechnology, Vol. 27, No. 36, 365709, 02.08.2016.

Research output: Contribution to journalArticle

Anjum, DH, Memon, NK, Ismail, M, Hedhili, MN, Sharif, U & Chung, SH 2016, 'Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles', Nanotechnology, vol. 27, no. 36, 365709. https://doi.org/10.1088/0957-4484/27/36/365709
Anjum, Dalaver H. ; Memon, Nasir K. ; Ismail, Mohamed ; Hedhili, Mohamed N. ; Sharif, Usman ; Chung, Suk Ho. / Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles. In: Nanotechnology. 2016 ; Vol. 27, No. 36.
@article{bd70404fcb274eb4a874466c3c2bd0c3,
title = "Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles",
abstract = "We present a study on the properties of iron (Fe)-doped and carbon (C)-coated titania (TiO2) nanoparticles (NPs) which has been compiled by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). These TiO2 NPs were prepared by using the flame synthesis method. This method allows the simultaneous C coating and Fe doping of TiO2 NPs. XRD investigations revealed that the phase of the prepared NPs was anatase TiO2. Conventional TEM analysis showed that the average size of the TiO2 NPs was about 65 nm and that the NPs were uniformly coated with the element C. Furthermore, from the x-ray energy dispersive spectrometry analysis, it was found that about 8 at.{\%} Fe was present in the synthesized samples. High-resolution TEM (HRTEM) revealed the graphitized carbon structure of the layer surrounding the prepared TiO2 NPs. HRTEM analysis further revealed that the NPs possessed the crystalline structure of anatase titania. Energy-filtered TEM (EFTEM) analysis showed the C coating and Fe doping of the NPs. The ratio of L3 and L2 peaks for the Ti-L23 and Fe-L23 edges present in the core loss electron energy loss spectroscopy (EELS) revealed a +4 oxidation state for the Ti and a +3 oxidation state for the Fe. These EELS results were further confirmed with XPS analysis. The electronic properties of the samples were investigated by applying Kramers-Kronig analysis to the low-loss EELS spectra acquired from the prepared NPs. The presented results showed that the band gap energy of the TiO2 NPs decreased from an original value of 3.2 eV to about 2.2 eV, which is quite close to the ideal band gap energy of 1.65 eV for photocatalysis semiconductors. The observed decrease in band gap energy of the TiO2 NPs was attributed to the presence of Fe atoms at the lattice sites of the anatase TiO2 lattice. In short, C-coated and Fe-doped TiO2 NPs were synthesized with a rather cost-effective and comparatively easily scalable method. The presented analysis enables us to predict the excellent efficiency of these NPs for solar-cell and photo-catalysis applications.",
keywords = "flame synthesis of nanoparticles, KramersKronig analysis, optical properties using EELS, transmission electron microscopy, x-ray photoelectron microscopy",
author = "Anjum, {Dalaver H.} and Memon, {Nasir K.} and Mohamed Ismail and Hedhili, {Mohamed N.} and Usman Sharif and Chung, {Suk Ho}",
year = "2016",
month = "8",
day = "2",
doi = "10.1088/0957-4484/27/36/365709",
language = "English",
volume = "27",
journal = "Nanotechnology",
issn = "0957-4484",
publisher = "IOP Publishing Ltd.",
number = "36",

}

TY - JOUR

T1 - Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles

AU - Anjum, Dalaver H.

AU - Memon, Nasir K.

AU - Ismail, Mohamed

AU - Hedhili, Mohamed N.

AU - Sharif, Usman

AU - Chung, Suk Ho

PY - 2016/8/2

Y1 - 2016/8/2

N2 - We present a study on the properties of iron (Fe)-doped and carbon (C)-coated titania (TiO2) nanoparticles (NPs) which has been compiled by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). These TiO2 NPs were prepared by using the flame synthesis method. This method allows the simultaneous C coating and Fe doping of TiO2 NPs. XRD investigations revealed that the phase of the prepared NPs was anatase TiO2. Conventional TEM analysis showed that the average size of the TiO2 NPs was about 65 nm and that the NPs were uniformly coated with the element C. Furthermore, from the x-ray energy dispersive spectrometry analysis, it was found that about 8 at.% Fe was present in the synthesized samples. High-resolution TEM (HRTEM) revealed the graphitized carbon structure of the layer surrounding the prepared TiO2 NPs. HRTEM analysis further revealed that the NPs possessed the crystalline structure of anatase titania. Energy-filtered TEM (EFTEM) analysis showed the C coating and Fe doping of the NPs. The ratio of L3 and L2 peaks for the Ti-L23 and Fe-L23 edges present in the core loss electron energy loss spectroscopy (EELS) revealed a +4 oxidation state for the Ti and a +3 oxidation state for the Fe. These EELS results were further confirmed with XPS analysis. The electronic properties of the samples were investigated by applying Kramers-Kronig analysis to the low-loss EELS spectra acquired from the prepared NPs. The presented results showed that the band gap energy of the TiO2 NPs decreased from an original value of 3.2 eV to about 2.2 eV, which is quite close to the ideal band gap energy of 1.65 eV for photocatalysis semiconductors. The observed decrease in band gap energy of the TiO2 NPs was attributed to the presence of Fe atoms at the lattice sites of the anatase TiO2 lattice. In short, C-coated and Fe-doped TiO2 NPs were synthesized with a rather cost-effective and comparatively easily scalable method. The presented analysis enables us to predict the excellent efficiency of these NPs for solar-cell and photo-catalysis applications.

AB - We present a study on the properties of iron (Fe)-doped and carbon (C)-coated titania (TiO2) nanoparticles (NPs) which has been compiled by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). These TiO2 NPs were prepared by using the flame synthesis method. This method allows the simultaneous C coating and Fe doping of TiO2 NPs. XRD investigations revealed that the phase of the prepared NPs was anatase TiO2. Conventional TEM analysis showed that the average size of the TiO2 NPs was about 65 nm and that the NPs were uniformly coated with the element C. Furthermore, from the x-ray energy dispersive spectrometry analysis, it was found that about 8 at.% Fe was present in the synthesized samples. High-resolution TEM (HRTEM) revealed the graphitized carbon structure of the layer surrounding the prepared TiO2 NPs. HRTEM analysis further revealed that the NPs possessed the crystalline structure of anatase titania. Energy-filtered TEM (EFTEM) analysis showed the C coating and Fe doping of the NPs. The ratio of L3 and L2 peaks for the Ti-L23 and Fe-L23 edges present in the core loss electron energy loss spectroscopy (EELS) revealed a +4 oxidation state for the Ti and a +3 oxidation state for the Fe. These EELS results were further confirmed with XPS analysis. The electronic properties of the samples were investigated by applying Kramers-Kronig analysis to the low-loss EELS spectra acquired from the prepared NPs. The presented results showed that the band gap energy of the TiO2 NPs decreased from an original value of 3.2 eV to about 2.2 eV, which is quite close to the ideal band gap energy of 1.65 eV for photocatalysis semiconductors. The observed decrease in band gap energy of the TiO2 NPs was attributed to the presence of Fe atoms at the lattice sites of the anatase TiO2 lattice. In short, C-coated and Fe-doped TiO2 NPs were synthesized with a rather cost-effective and comparatively easily scalable method. The presented analysis enables us to predict the excellent efficiency of these NPs for solar-cell and photo-catalysis applications.

KW - flame synthesis of nanoparticles

KW - KramersKronig analysis

KW - optical properties using EELS

KW - transmission electron microscopy

KW - x-ray photoelectron microscopy

UR - http://www.scopus.com/inward/record.url?scp=84988442259&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84988442259&partnerID=8YFLogxK

U2 - 10.1088/0957-4484/27/36/365709

DO - 10.1088/0957-4484/27/36/365709

M3 - Article

VL - 27

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 36

M1 - 365709

ER -