Photocurrents at polarized liquid|liquid interfaces enhanced by a gold nanoparticle film

Photocurrent responses associated with the interfacial quenching of the photo-excited water-soluble zinc meso-tetra(4-carboxyphenyl)porphyrin (ZnTPPC) by ferrocene have been studied at a water|1,2-dichloroethane interface in the absence and in the presence of adsorbed gold nanoparticles. Upon addition of methanol, a mirror-like gold film is formed and an important enhancement of the photocurrent response can be observed. Intensity modulated photocurrent spectroscopy experiments (IMPS) have been performed, in order to deconvolute in the frequency domain the contribution from the competition between the recombination and the product separation arising after the electron transfer, and the attenuation associated with the resistance and interfacial capacitance (RCint) time constant of the cell

Artificial Photosynthesis at Soft Interfaces

The concept of artificial photosynthesis at a polarised liquid membrane is presented. It includes two photosystems, one at each interface for the hydrogen and oxygen evolution respectively. Both reactions involve proton coupled electron transfer reactions, and some ultrafast steps at the photosensitization stage

Self-Assembled Molecular Rafts at Liquid|Liquid Interfaces for Four-Electron Oxygen Reduction

The self-assembly of the oppositely charged watersoluble porphyrins, cobalt tetramethylpyridinium porphyrin (CoTMPyP4+) and cobalt tetrasulphonatophenyl porphyrin (CoTPPS4−), at the interface with an organic solvent to form molecular “rafts”, provides an excellent catalyst to perform the interfacial four-electron reduction of oxygen by lipophilic electron donors such as tetrathiafulvalene (TTF). The catalytic activity and selectivity of the self-assembled catalyst toward the four-electron pathway was found to be as good as that of the Pacman type cofacial cobalt porphyrins. The assembly has been characterized by UV−visible spectroscopy, Surface Second Harmonic Generation, and Scanning Electron Microscopy. Density functional theory calculations confirm the possibility of formation of the catalytic CoTMPyP4+/ CoTPPS4− complex and its capability to bind oxygen