Characterization and photocatalytic activity for methylene blue degradation of iron-deposited TiO2 photocatalyst
(1. Guangzhou Institute of Energy Conversion,
the Chinese Academy of Science, Guangzhou 510070, China;
2. College of Science, South China Agricultural University,
Guangzhou 510642, China;
3. Guangdong Institute of Eco-Environment and Soil Science,
Guangzhou 510650, China)
the Chinese Academy of Science, Guangzhou 510070, China;
2. College of Science, South China Agricultural University,
Guangzhou 510642, China;
3. Guangdong Institute of Eco-Environment and Soil Science,
Guangzhou 510650, China)
Abstract: Iron-deposited TiO2 was prepared by photo-reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO2 was deposited with iron, and the optimum n(Fe)/n(Ti) is 0.25%. TiO2 and iron-deposited TiO2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe3+ and Fe2+ are present on the surface of 0.5% iron-deposited TiO2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe3+/Fe2+ couple seems plausible, but Fe2+ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO2, because iron deposited traps photo-generated electrons and holes. The fluorescence intensity order of TiO2 and iron-deposited TiO2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO2 and iron-deposited TiO2, from low to high.
Key words: methylene blue; iron deposited TiO2; TiO2;photocatalytic degradation