Photocatalytic water splitting using sol-gel prepared Pt/SrTiO3:Rh in twin membrane reactor via Ce ions mediator by visible light irradiation
Date Issued
2011
Date
2011
Author(s)
Chang, Cheng-Wei
Abstract
With the increasing demand for energy in the industrial society, using solar energy to produce hydrogen by water splitting is an alternative clean and pollution-free way to produce energy. Z-scheme system is the use of two different kinds of photocatalysts to do half-reaction of water splitting , respectively, and the use of different transmission medias to transmit electrons and holes, and finally completes the whole reaction. Previous studies in our laboratory point out that the use of pretreated Nafion membrane to separate the different reaction catalyst systems, not only to pass through ion transfer mediator by diffusion effect, but also to separate hydrogen and oxygen, and thus enhance the production. In this study, first we use sol-gel method to produce Pt/SrTiO3:Rh catalyst as hydrogen production, then put it in 10vol% methanol aqueous solution to do the test of hydrogen production activity in visible light , and hydrogen production can reach 10 µmol / gcat within 6 hours. We found that at pH 1.5 the catalytic activity is the best. Producing SrTiO3 by sol-gel method can get higher activity than using solid-state method and hydrothermal method. Secondly, we add BiVO4 as oxygen production into the twin membrane reactor, and Ce4+/Ce3+ as ion transfer mediators in the aqueous solution, and use Nafion cation exchange membrane to separate the two catalysts to do water decomposition in visible light. Besides , the membrane can separate hydrogen and oxygen. In our study we use 300W xenon lamp as the visible light source and Ce4+ pre-treated Nafion membrane to separate two sides of half-reaction. The result is that the hydrogen production can be achieved certain level, and that in line with H2/O2 = 2 stoichiometric decomposition of water. Pt/SrTiO3:Rh is prepared by Sol-gel method with light deposition method, and BiVO4 is produced by liquid phase synthesis. The use of double-membrane reactor can reduce the chance of reversing reaction of hydrogen and oxygen, therefore it enhance hydrogen production rate. Separating two sides of the catalysts can also solve the problem of competitive absorption of light. We expect to test the best reaction conditions in the presence of cerium ions in order to improve the hydrogen production performance.
Subjects
Photocatalytic water splitting
ion transportation
hydrogen evolution
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-100-R98524047-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):1c75d1c8a65d28b2239ac5709d63975c