One-electron redox processes during polyoxometalate-mediated photocatalytic reactions of TiO(2) studied by two-color two-laser flash photolysis |
| |
Authors: | Tachikawa Takashi Tojo Sachiko Fujitsuka Mamoru Majima Tetsuro |
| |
Institution: | The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan. |
| |
Abstract: | The one-electron redox processes of several compounds during polyoxometalate (POM)-mediated photocatalytic reactions of TiO(2) were investigated using the two-color two-laser flash-photolysis technique. The efficiency of the one-electron oxidation of aromatic sulfides by the trapped hole (h(tr) (+)) or the surface-bound OH radical (OH(s) (.)) is found to be significantly enhanced due to electron transfer from the conduction band (CB) of TiO(2) to the POM. The efficiency of the electron transfer from the CB of TiO(2) to the POM decreases in the order H(2)W(12)O(40) (6-) < SiW(12)O(40) (4-) < PW(12)O(40) (3-), that is, it depends on the reduction potential (E(red)) of the POMs. Electron injection from PW(12)O(40) (4-) in the excited state (PW(12)O(40) (4-*)) to the CB of TiO(2) was clearly observed using the two-color two-laser flash-photolysis technique. Storage of electrons in the TiO(2)/PW(12)O(40) (3-)/methyl viologen (MV(2+)) ternary system was also achieved upon two-color two-laser irradiation. |
| |
Keywords: | electron transfer photochemistry polyoxometalates radical ions titanium oxide |
本文献已被 PubMed 等数据库收录! |