Photocatalytic hydrogen production with non-stoichiometric pyrochlore bismuth titanate
- authored by
- 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.
- Organisation(s)
-
Institute of Technical Chemistry
- Type
- Article
- Journal
- Catalysis today
- Volume
- 225
- Pages
- 102-110
- No. of pages
- 9
- ISSN
- 0920-5861
- Publication date
- 15.04.2014
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Catalysis, General Chemistry
- Sustainable Development Goals
- SDG 7 - Affordable and Clean Energy
- Electronic version(s)
-
https://doi.org/10.1016/j.cattod.2013.09.009 (Access:
Closed)
