%0 Journal Article
%A Reitz, Christian
%A Smarsly, Bernd
%A Brezesinski, Torsten
%T General Synthesis of Ordered Mesoporous Rare-Earth Orthovanadate Thin Films and Their Use as Photocatalysts and Phosphors for Lighting Applications
%J ACS applied nano materials
%V 2
%N 2
%@ 2574-0970
%C Washington, DC
%I ACS Publications
%M PUBDB-2019-01329
%P 1063 - 1071
%D 2019
%Z © American Chemical Society
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000469409900049
%R 10.1021/acsanm.8b02327
%U https://bib-pubdb1.desy.de/record/420142