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Photocurrent response and semiconductor characteristics of Ce-Ce2O3-CeO2-modified TiO2 nanotube arrays.

Tan Y, Zhang S, Liang K - Nanoscale Res Lett (2014)

Bottom Line: Then, the TNT electrodes were deposited of Ce by cathodic reduction of Ce(NO3)3 6H2O.The Ce-deposited TNTs (band gap energy Eg = 2.92 eV) exhibited enhanced photocurrent responses under visible light region and indicated more negative flat band potential (Efb) compared with the TNTs without deposition.The photocurrent responses and Efb were found to be strongly dependent on the contents of Ce2O3 and CeO2 deposited on TNTs.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Environment Science and Engineering, North China Electric Power University, Yonghua North Street 619#, Baoding 071003, China. kexin91802@163.com.

ABSTRACT
We reported Ce and its oxide-modified TiO2 nanotube arrays (TNTs) and their semiconductor properties. The TNTs were prepared by anodic oxidation on pure Ti and investigated by electrochemical photocurrent response analysis. Then, the TNT electrodes were deposited of Ce by cathodic reduction of Ce(NO3)3 6H2O. After deposition, the TNT electrodes were fabricated by anodic oxidation at E = 1.0 V(SCE) for various electricity as Ce-Ce2O3-CeO2 modification. The Ce-deposited TNTs (band gap energy Eg = 2.92 eV) exhibited enhanced photocurrent responses under visible light region and indicated more negative flat band potential (Efb) compared with the TNTs without deposition. After anodic oxidation, the mixed Ce and its oxide (Ce2O3-CeO2)-modified TNT photoelectrodes exhibited higher photocurrent responses under both visible and UV light regions than the TNTs without deposition. The photocurrent responses and Efb were found to be strongly dependent on the contents of Ce2O3 and CeO2 deposited on TNTs. A new characteristic of Eg = 2.1 ± 0.1 eV was investigated in the Ce2O3- and CeO2-modified photoelectrodes. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were also employed to characterize various modified TNTs photoelectrodes.

No MeSH data available.


Photocurrent analysis results. (A) Photocurrent responses vs. wavelength plots. (B) Photocurrent responses vs. photon energy plots. (C) Low photon energy part of Figure 3B (from 2.0 to 3.0 eV).
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Figure 3: Photocurrent analysis results. (A) Photocurrent responses vs. wavelength plots. (B) Photocurrent responses vs. photon energy plots. (C) Low photon energy part of Figure 3B (from 2.0 to 3.0 eV).

Mentions: The photocurrent spectra vs. wavelength are showed in Figure 3A. The TNTs-Ce indicates stronger photocurrent response in visible light region and weaker photocurrent response in UV light region compared to the TNTs without deposition. After anode oxidation, Ce-Ce2O3-CeO2 modification photoelectrodes showed stronger photocurrent response in visible. In UV light region, the photocurrents responses of the photoelectrodes are reinforced as oxidation electricity increases with CeO2 increasing except TNTs-0.00001 C. The reason could be as followed: the Ce4+ is an efficient electron acceptor during the photocurrent production. But the deposition of Ce and its oxide affect the surface morphology of TNTs (Figure 2B) which reduced the absorption of light. In visible light region as the oxidation in depth with Ce2O3 is increasing, firstly, the photocurrent responses of the TNTs-0.00001 C, TNTs-0.00025 C, and TNTs-0.005 C are gradually increased; then, the photocurrent response of TNTs-0.01 C is slightly decreased by Ce2O3 transfer to CeO2.


Photocurrent response and semiconductor characteristics of Ce-Ce2O3-CeO2-modified TiO2 nanotube arrays.

Tan Y, Zhang S, Liang K - Nanoscale Res Lett (2014)

Photocurrent analysis results. (A) Photocurrent responses vs. wavelength plots. (B) Photocurrent responses vs. photon energy plots. (C) Low photon energy part of Figure 3B (from 2.0 to 3.0 eV).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016308&req=5

Figure 3: Photocurrent analysis results. (A) Photocurrent responses vs. wavelength plots. (B) Photocurrent responses vs. photon energy plots. (C) Low photon energy part of Figure 3B (from 2.0 to 3.0 eV).
Mentions: The photocurrent spectra vs. wavelength are showed in Figure 3A. The TNTs-Ce indicates stronger photocurrent response in visible light region and weaker photocurrent response in UV light region compared to the TNTs without deposition. After anode oxidation, Ce-Ce2O3-CeO2 modification photoelectrodes showed stronger photocurrent response in visible. In UV light region, the photocurrents responses of the photoelectrodes are reinforced as oxidation electricity increases with CeO2 increasing except TNTs-0.00001 C. The reason could be as followed: the Ce4+ is an efficient electron acceptor during the photocurrent production. But the deposition of Ce and its oxide affect the surface morphology of TNTs (Figure 2B) which reduced the absorption of light. In visible light region as the oxidation in depth with Ce2O3 is increasing, firstly, the photocurrent responses of the TNTs-0.00001 C, TNTs-0.00025 C, and TNTs-0.005 C are gradually increased; then, the photocurrent response of TNTs-0.01 C is slightly decreased by Ce2O3 transfer to CeO2.

Bottom Line: Then, the TNT electrodes were deposited of Ce by cathodic reduction of Ce(NO3)3 6H2O.The Ce-deposited TNTs (band gap energy Eg = 2.92 eV) exhibited enhanced photocurrent responses under visible light region and indicated more negative flat band potential (Efb) compared with the TNTs without deposition.The photocurrent responses and Efb were found to be strongly dependent on the contents of Ce2O3 and CeO2 deposited on TNTs.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Environment Science and Engineering, North China Electric Power University, Yonghua North Street 619#, Baoding 071003, China. kexin91802@163.com.

ABSTRACT
We reported Ce and its oxide-modified TiO2 nanotube arrays (TNTs) and their semiconductor properties. The TNTs were prepared by anodic oxidation on pure Ti and investigated by electrochemical photocurrent response analysis. Then, the TNT electrodes were deposited of Ce by cathodic reduction of Ce(NO3)3 6H2O. After deposition, the TNT electrodes were fabricated by anodic oxidation at E = 1.0 V(SCE) for various electricity as Ce-Ce2O3-CeO2 modification. The Ce-deposited TNTs (band gap energy Eg = 2.92 eV) exhibited enhanced photocurrent responses under visible light region and indicated more negative flat band potential (Efb) compared with the TNTs without deposition. After anodic oxidation, the mixed Ce and its oxide (Ce2O3-CeO2)-modified TNT photoelectrodes exhibited higher photocurrent responses under both visible and UV light regions than the TNTs without deposition. The photocurrent responses and Efb were found to be strongly dependent on the contents of Ce2O3 and CeO2 deposited on TNTs. A new characteristic of Eg = 2.1 ± 0.1 eV was investigated in the Ce2O3- and CeO2-modified photoelectrodes. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were also employed to characterize various modified TNTs photoelectrodes.

No MeSH data available.