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Photoluminescence of urea- and urea/rhodamine B-capped TiO2 nanoparticles

Gonzalo-Juan, I. ; Macé, L. ; Tengeler, S. ; Mosallem, A. ; Nicoloso, N. ; Riedel, R. (2016)
Photoluminescence of urea- and urea/rhodamine B-capped TiO2 nanoparticles.
In: Materials Chemistry and Physics, 177
doi: 10.1016/j.matchemphys.2016.04.057
Article, Bibliographie

Abstract

Urea- and rhodamine B (RhB)-capped TiO2 nanoparticles (NPs) have been prepared by solvothermal synthesis and characterized by HRTEM, XRD, FTIR, XPS, optical absorption and photoemission. The urea and urea/RhB ligands are capped to the surface of the TiO2 NPs for the first time through carbamate bonding. The band gap of TiO2 is slightly reduced from 3.1 eV to 3.0 eV in the urea capped TiO2 NPs (TU) and 2.9 eV for the NPs capped with urea/RhB (TUR). The generation of new trapping states in TU and TUR at the conduction band edges (surface oxygen vacancies) has been confirmed by the Urbach law providing tail state energies of 180 meV and 270 meV, respectively. These tail states are considered to be responsible for the strong reduction of the photoluminescence at ≈400 nm and the increased emission at ≈600 nm in TU and TUR. The findings suggest that urea- and RhB-capped TiO2 NPs could have potential applications as photocatalysts, opto-electronic devices, sensors, biological labels and anti-bacterial agents.

Item Type: Article
Erschienen: 2016
Creators: Gonzalo-Juan, I. ; Macé, L. ; Tengeler, S. ; Mosallem, A. ; Nicoloso, N. ; Riedel, R.
Type of entry: Bibliographie
Title: Photoluminescence of urea- and urea/rhodamine B-capped TiO2 nanoparticles
Language: English
Date: 1 July 2016
Publisher: Elsevier Science Publishing
Journal or Publication Title: Materials Chemistry and Physics
Volume of the journal: 177
DOI: 10.1016/j.matchemphys.2016.04.057
Abstract:

Urea- and rhodamine B (RhB)-capped TiO2 nanoparticles (NPs) have been prepared by solvothermal synthesis and characterized by HRTEM, XRD, FTIR, XPS, optical absorption and photoemission. The urea and urea/RhB ligands are capped to the surface of the TiO2 NPs for the first time through carbamate bonding. The band gap of TiO2 is slightly reduced from 3.1 eV to 3.0 eV in the urea capped TiO2 NPs (TU) and 2.9 eV for the NPs capped with urea/RhB (TUR). The generation of new trapping states in TU and TUR at the conduction band edges (surface oxygen vacancies) has been confirmed by the Urbach law providing tail state energies of 180 meV and 270 meV, respectively. These tail states are considered to be responsible for the strong reduction of the photoluminescence at ≈400 nm and the increased emission at ≈600 nm in TU and TUR. The findings suggest that urea- and RhB-capped TiO2 NPs could have potential applications as photocatalysts, opto-electronic devices, sensors, biological labels and anti-bacterial agents.

Uncontrolled Keywords: Ceramics, Organic compounds, Optical properties, Luminescence
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
11 Department of Materials and Earth Sciences > Material Science > Surface Science
Date Deposited: 07 Jun 2016 08:25
Last Modified: 27 Sep 2017 08:33
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