NiII1,4,8,11-tetraazacyclotetradecane electrocatalytic films prepared on top of surface anchored PAMAM dendrimer layers. A new type of electrocatalytic material for the electrochemical oxidation of methanol.
Gold electrodes, previously prepared with surface anchored PAMAM dendrimers, were further modified with a Ni-containing tetraazamacrocycle resulting in a novel electrocatalytic material which proved to be particularly efficient for the electrochemical oxidation of methanol in basic aqueous medium.
Molecular and biomolecular optoelectronics
Abstract Reversible electronic transduction of photonic processes occurring on electrodes is the conceptual method to develop molecular and biomolecular optoelectronic systems. Cyclic photochemical activation of molecular or biomolecular monolayer redox-functions provides a general methodology for the amperometric transduction of photonic information that is recorded by the chemical assembly. Alternatively, photoisomerizable monolayers associated with electrodes act as "command interfaces" for controlling the interfacial electron transfer between molecular redox-species or redox-proteins. The systems use a photonic input for the generation of an electronic output and act as information processing assemblies. Programmed arrays of photosensitizer/electron acceptor cross-linked Au-nanoparticle arrays are assembled on indium tin oxide (ITO) for photoelectrochemical applications.
Electrochemistry of conducting polypyrrole films containing cobalt porphyrin: Part 2. New developments and inclusion of metallic aggregates in the coordination polymer
The electrochemical polymerization of a pyrrole-substituted cobalt porphyrin complex (i.e. 5-(3-(4-(1-pyrrolyl)butyl)phenoxy)-10,15,20-tritolylporphine cobalt) has been performed in acetonitrile + tetrabutylammonium tetrafluoroborate solution. The redox properties of the film were examined by cyclic voltammetry and chronoamperometry. The voltammograms of these films exhibited a reversible process for the Co(II)/Co(I) reaction at a formal potential of −0.90 V (vs. SCE). Using chronoamperometry, quantitative analysis of the curves allowed us to extract the diffusion coefficient D for the Co(II)/Co(I) step of the cobalt porphyrin film, D = 1.46×10−11cm2 s−1. The cobalt porphyrin content was estimated by cyclic voltammetry, and this shows that thick polymers act as insulators in the low potential range E < −1 V (vs. SCE). Electroreductive inclusion of Pt and Ag aggregates in these coordination polymers from K2PtCl4, H2PtCl6 and AgClO4 solutions was concluded. Evidence that metallic particles were included in the polymer films was provided by scanning electron microscopy coupled with X-ray fluorescence analysis.