Photocatalytic hydrogen production with non-stoichiometric pyrochlore bismuth titanate
- verfasst von
- O. Merka, D.W. Bahnemann, M. Wark
- Abstract
Pyrochlore bismuth titanate (Bi
2-xTi
0.75x)Ti
2O
7 was prepared by an aqueous sol-gel method and annealed at different temperatures. Non-stoichiometry was obtained by adjusting the Ti/Bi ratio during synthesis. Additionally the two bismuth titanate phases Bi
4Ti
3O
12 and Bi
2Ti
4O
11 were synthesized. The materials were characterized by X-ray diffraction and UV-vis reflectance spectroscopy. Photocatalytic hydrogen production was tested in the presence of methanol as sacrificial agent after loading the bismuth titanates with nanoparticles of platinum acting as co-catalysts. It was found that stoichiometric Bi
2Ti
2O
7 being completely inactive could be turned into a good photocatalyst by increasing the Ti/Bi ratio to 1.50 corresponding to (Bi
1.55Ti
0.33)Ti
2O
7 still crystallizing in a pure pyrochlore phase. The increase in activity is supposed to derive from an optimization of the TiO
6-octahedral geometry due to the generation of bismuth and oxygen vacancies in the lattice. If platinum is applied as co-catalyst on (Bi
2-xTi
0.75x)Ti
2O
7 samples, stability issues occur during photocatalysis, which are suppressed by coating the platinum particles with a Cr
2O
3 shell.
- Organisationseinheit(en)
-
Institut für Technische Chemie
- Typ
- Artikel
- Journal
- Catalysis today
- Band
- 225
- Seiten
- 102-110
- Anzahl der Seiten
- 9
- ISSN
- 0920-5861
- Publikationsdatum
- 15.04.2014
- Publikationsstatus
- Veröffentlicht
- Peer-reviewed
- Ja
- ASJC Scopus Sachgebiete
- Katalyse, Allgemeine Chemie
- Ziele für nachhaltige Entwicklung
- SDG 7 – Erschwingliche und saubere Energie
- Elektronische Version(en)
-
https://doi.org/10.1016/j.cattod.2013.09.009 (Zugang:
Geschlossen)
