P210
Photoinduced Hydrogen Production by Zinc Tetraphenylporphin Confined in a Polymer Matrix
Abe Toshiyuki, Masao Kaneko
Ibaraki University

Photoinduced proton reduction to produce H2 was found in the system using zinc tetraphenylporphin (ZnTPP) incorporated into a NafionƒB membrane coated on a platinum electrode (denoted as Pt/Nf[ZnTPP]). When visible light (ƒÉ>390 nm) was irradiated on the Pt/Nf[ZnTPP] system, photocurrent was generated under applied potentials below -0.10 V (vs. Ag/AgCl). The action spectrum for the photocurrent agreed with the absorption spectrum of the Nf[ZnTPP] membrane, showing that the present photochemical process is induced on the light absorption by ZnTPP. By measuring the emission decay of ZnTPP under the photoelectrochemical conditions, it was exhibited that the emission from the singlet excited ZnTPP is quenched by the cathodic potentials. This indicated that, in the photochemical primary process, a reductive quenching takes place by electron injection from the Pt electrode to the singlet excited ZnTPP forming ZnTPPE- which works as a reductant f! or the H2 formation.
Return to Program.