Photocurrent-Boosting by Intramembrane Electron Mediation between Titania Nanoparticles Dispersed into Nafion−Porphyrin Composites

We have used titania nanoparticles (TiO 2 ) to establish a facile preparation of a highly photoresponsible membrane. An improved photocurrent generator was prepared easily using spin coating of a Nafion/porphyrin/TiO 2 mixture on an indium−tin−oxide substrate. Generated photocurrent density was about 10 times higher than that in the absence of TiO 2 . The resultant electrode shows distinct photocurrent generation despite impediments derived from high dye-concentration (i.e., self-quenching of photoexcited states) and membrane thickness (i.e., losses of electron flow passing through membrane into electrode). Photocurrent densities increased linearly concomitant with high surface concentrations of porphyrin and high membrane thickness. It became evident that TiO 2 contributes to more efficient photocurrent generation by intramembrane electron mediation.