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Solar conversion of water into the storable energy carrier H2 can be achieved through photoelectrochemical water splitting using light adsorbing anodes and cathodes bearing O2 and H2 evolving catalysts, respectively. Herein a novel photocathode nanohybrid system is reported. This photocathode consists of a dye-sensitized p-type nickel oxide (NiO) with a perylene-based chromophore (PCA) and a tetra-adamantane modified cobaloxime reduction catalyst (Co) that photo-reduces aqueous protons to H2. An original supramolecular approach was employed, using β-cyclodextrin functionalized gold nanoparticles (β-CD-AuNPs) to link the alkane chain of the PCA dye to the adamantane moieties of the cobaloxime catalyst (Co). This new architecture was investigated by photoelectrochemical measurements and via femtosecond-transient absorption spectroscopy. The results show that irradiation of the complete NiO‖PCA‖β-CD-AuNPs‖Co electrode leads to ultrafast hole injection into NiO (π = 3 ps) from the excited dye, followed by rapid reduction of the catalyst, and finally H2 evolution. [ABSTRACT FROM AUTHOR]

A biocathode was designed by the modification of a carbon nanotube (CNT) gas-diffusion electrode with bilirubin oxidase from Bacillus pumilus, achieving high current densities up to 3 mA cm−2 for the reduction of O2 from air. A membraneless air-breathing hydrogen biofuel cell was designed by combination of this cathode with a functionalized CNT-based hydrogenase anode. [ABSTRACT FROM AUTHOR]

We report the functionalization of multi-walled carbon nanotube (MWCNT) electrodes by oxidative electropolymerization of pyrrole monomers bearing pyrene and N-hydroxysuccinimide groups. Both polymers were applied to the immobilization and electrical wiring of Trametes versicolor laccase via chemical grafting or non-covalent binding. A “pseudo” host–guest interaction of polymerized pyrene with a hydrophobic cavity of laccase was used for the oriented enzyme immobilization on MWCNT electrodes. The latter leads to higher catalytic current for oxygen reduction (1.85 mA cm−2) and higher electroenzymatic stability (50% after one month). [ABSTRACT FROM AUTHOR]

Solar conversion of water into the storable energy carrier H 2 can be achieved through photoelectrochemical water splitting using light adsorbing anodes and cathodes bearing O 2 and H 2 evolving catalysts, respectively. Herein a novel photocathode nanohybrid system is reported. This photocathode consists of a dye-sensitized p-type nickel oxide (NiO) with a perylene-based chromophore ( PCA ) and a tetra-adamantane modified cobaloxime reduction catalyst ( Co ) that photo-reduces aqueous protons to H 2 . An original supramolecular approach was employed, using β-cyclodextrin functionalized gold nanoparticles ( β-CD-AuNPs ) to link the alkane chain of the PCA dye to the adamantane moieties of the cobaloxime catalyst ( Co ). This new architecture was investigated by photoelectrochemical measurements and via femtosecond-transient absorption spectroscopy. The results show that irradiation of the complete NiO| PCA|β-CD-AuNPs|Co electrode leads to ultrafast hole injection into NiO (π = 3 ps) from the excited dye, followed by rapid reduction of the catalyst, and finally H 2 evolution.

The influence of anions on tautomerism in benzimidazole containing anion receptors has been studied via a variety of techniques in both solution and the solid state. The results show that hydrogen bonding interactions between the receptors and guests have a significant effect of the nature of the tautomer present. The compounds show a preference for complexation of lactate over pyruvate.

Tautomeric switching is observed in a series of benzimidazole-based anion receptors upon addition of basic anions. An N-methylbenzimidazole based receptor selectively interacts with dihydrogen phosphate over a variety of other putative anionic guests via a combination of donated and accepted hydrogen bonds.