TU Darmstadt / ULB / TUbiblio

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

Gonzalo-Juan, I. and Macé, L. and Tengeler, S. and Mosallem, A. and Nicoloso, N. and Riedel, R. (2016):
Photoluminescence of urea- and urea/rhodamine B-capped TiO2 nanoparticles.
In: Materials Chemistry and Physics, Elsevier Science Publishing, pp. 472-478, 177, ISSN 02540584,
[Online-Edition: http://dx.doi.org/10.1016/j.matchemphys.2016.04.057],
[Article]

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. and Macé, L. and Tengeler, S. and Mosallem, A. and Nicoloso, N. and Riedel, R.
Title: Photoluminescence of urea- and urea/rhodamine B-capped TiO2 nanoparticles
Language: English
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.

Journal or Publication Title: Materials Chemistry and Physics
Volume: 177
Publisher: Elsevier Science Publishing
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
Official URL: http://dx.doi.org/10.1016/j.matchemphys.2016.04.057
Identification Number: doi:10.1016/j.matchemphys.2016.04.057
Export:
Suche nach Titel in: TUfind oder in Google

Optionen (nur für Redakteure)

View Item View Item