TY  - JOUR
AU  - Reitz, Christian
AU  - Smarsly, Bernd
AU  - Brezesinski, Torsten
TI  - General Synthesis of Ordered Mesoporous Rare-Earth Orthovanadate Thin Films and Their Use as Photocatalysts and Phosphors for Lighting Applications
JO  - ACS applied nano materials
VL  - 2
IS  - 2
SN  - 2574-0970
CY  - Washington, DC
PB  - ACS Publications
M1  - PUBDB-2019-01329
SP  - 1063 - 1071
PY  - 2019
N1  - © American Chemical Society
AB  - The block copolymer templating sol–gel synthesis of a novel class of ternary oxide nanomaterials is reported. NdVO<sub>4</sub>, EuVO<sub>4</sub>, GdVO<sub>4</sub>, DyVO<sub>4</sub>, YVO<sub>4</sub>, and TmVO<sub>4</sub> have been prepared as open mesoporous films by the dip-coating method using hydrated rare-earth nitrate salt precursors along with vanadium oxytrichloride. All materials crystallize in the tetragonal ZrSiO<sub>4</sub>-type structure with space group I4<sub>1</sub>/amd. Short-term treatment at 550 °C is found sufficient to initiate crystallization. Characterization via X-ray and electron diffraction, Raman and X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry confirms the single-phase nature and uniformity of the different orthovanadates with tailorable crystallite sizes. The integrated results from electron and atomic force microscopy, Kr physisorption, and in situ and ex situ synchrotron-based small-angle X-ray scattering reveal that the porosity persists throughout the thickness of films, and the mesoscopic ordering is retained even after heating in air at 700 °C. Photobleaching experiments indicate that the sol–gel derived materials, showing an indirect band gap transition at 3.8 ± 0.1 eV, exhibit good photocatalytic properties—the activity is highly superior to that of bulk films of the same nominal composition. Moreover, when doping GdVO<sub>4</sub>, YVO<sub>4</sub>, and solid solution GdVO<sub>4</sub>–YVO<sub>4</sub> with trivalent rare-earth ions such as Eu<sup>3+</sup>, Dy<sup>3+</sup>, Er<sup>3+</sup>, or Tm<sup>3+</sup> ions, the films hold promise as phosphors for lighting applications, which might pave the way toward development of (3-dimensional) intricate nanocomposites with unprecedented functionalities.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000469409900049
DO  - DOI:10.1021/acsanm.8b02327
UR  - https://bib-pubdb1.desy.de/record/420142
ER  -