Gold nanoparticles-enhanced photocurrent at a dye-sensitized liquid|liquid interface

Heterogeneous photoinduced electron transfer between a hydrophilic dye, 5,10,15,20-tetrakis(4-carboxypheny)porphyrinato zinc(II) (ZnTPPC4−), and a lipophilic quencher, ferrocene, across the polarized water|1,2-dichloroethane interface was studied in the presence of citrate-stabilized gold nanoparticles (Au-NPs). A positive photocurrent arising from the photoreduction of ZnTPPC4- was significantly enhanced by adding Au-NPs. The photocurrent enhancement was dependent on the concentration of Au-NPs, the excitation wavelength, and the polarization angle of the excitation light, respectively. The results demonstrated that Au-NPs act as effective photoreaction catalysts at the liquid|liquid interface.

► Distinct enhancement of the photoreaction yield in the presence of Au-NPs.
► Au-NPs catalyzed the heterogeneous photoinduced electron transfer across the liquid|liquid interface.
► Characteristic dependence of the photocurrent on the polarization angle of the excitation beam.