Enhanced Visible Light Controlled Glucose Photo-Reforming Using a Composite WO/Ag/TiO Photoanode: Effect of Incorporated Plasmonic Ag Nanoparticles.

WO/Ag/TiO composite photoelectrodes were formed via the high-temperature calcination of a WO film, followed by the sputtering of a very thin silver film and deposition of an overlayer of commercial TiO nanoparticles. These synthetic photoanodes were characterized in view of the oxidation of a model organic compound glucose combined with the generation of hydrogen at a platinum cathode. During prolonged photoelectrolysis under simulated solar light, these photoanodes demonstrated high and stable photocurrents of ca.

Photoelectrochemical Behavior of WO in an Aqueous Methanesulfonic Acid Electrolyte.

N-type semiconducting WO is widely investigated as a photoanode operating in water and seawater splitting devices. Because of the propensity of WO to favor photo-oxidation of acidic electrolyte anions and, in parallel, the formation on the electrode surface of the peroxo species, the choice of the appropriate electrolyte to allow stable operation of the photoanode is of critical importance. Our results from structural and photoelectrochemical tests performed using mesoporous WO photoanodes exposed to 80 h long photoelectrolysis in a 1 M aq.

Photoelectrocatalytic hydrogen generation coupled with reforming of glucose into valuable chemicals using a nanostructured WO photoanode.

Coupling the photo-oxidation of biomass derived substrates with water splitting in a photoelectrochemical (PEC) cell is a broadly discussed approach intended to enhance efficiency of hydrogen generation at the cathode. Here, we report a PEC device employing a nanostructured semitransparent WO photoanode that, irradiated with simulated solar light achieves large photocurrents of 6.5 mA cm through oxidation of glucose, a common carbohydrate available in nature that can be obtained by processing waste biomass.

Solar-Driven Water Oxidation and Decoupled Hydrogen Production Mediated by an Electron-Coupled-Proton Buffer.

Solar-to-hydrogen photoelectrochemical cells (PECs) have been proposed as a means of converting sunlight into H2 fuel. However, in traditional PECs, the oxygen evolution reaction and the hydrogen evolution reaction are coupled, and so the rate of both of these is limited by the photocurrents that can be generated from the solar flux. This in turn leads to slow rates of gas evolution that favor crossover of H2 into the O2 stream and vice versa, even through ostensibly impermeable membranes such as Nafion.

Enhanced water splitting at thin film tungsten trioxide photoanodes bearing plasmonic gold-polyoxometalate particles.

Tungsten trioxide (WO3) is one of a few stable semiconductor materials liable to produce solar fuel by photoelectrochemical water splitting. To enhance its visible light conversion efficiency, we incorporated plasmonic gold nanoparticles (Au NPs) derivatized with polyoxometalate (H3PMo12O40) species into WO3. The combined plasmonic and catalytic effect of Au NPs anchored to the WO3 surface resulted in a large increase of water photooxidation currents.

A highly stable, efficient visible-light driven water photoelectrolysis system using a nanocrystalline WO3 photoanode and a methane sulfonic acid electrolyte.

Nanostructuring of semiconductor films offers the potential means for producing photoelectrodes with improved minority charge carrier collection. Crucial to the effective operation of the photoelectrode is also the choice of a suitable electrolyte. The behaviour of the nanostructured WO(3) photoanodes in methane sulfonic acid solutions, which allow one to obtain large, perfectly stable visible-light driven water splitting photocurrents, is discussed.

Metal oxide photoanodes for water splitting.

Solar hydrogen production through photocatalytically assisted water splitting has attracted a great deal of attention since its first discovery almost 30 years ago. The publication of investigations into the use of TiO₂ photoanodes has continued apace since and a critical review of current trends is reported herein. Recent advances in the understanding of the behaviour of nanoparticulate TiO₂ films is summarized along with a balanced report into the utility and nature of titania films doped with non-metallic elements and ordered, nanostructured films such as those consisting of nanotubes.

Photoelectrochemical oxidation of water at transparent ferric oxide film electrodes.

The fabrication of thin-film Fe(2)O(3) photoanodes from the spray pyrolysis of Fe(III)-containing solutions is reported along with their structural characterization and application to the photoelectrolysis of water. These films combine good performance, measured in terms of photocurrent density, with excellent mechanical stability. A full investigation into the effects that modifications of the spray-pyrolysis method, such as the addition of dopants or structure-directing agents and changes in precursor species or carrier solvent, have on the performance of the photoanodes has been realized.

Electrochemistry of unfolded cytochrome c in neutral and acidic urea solutions.

The present investigation reports the first experimental measurements of the reorganization energy of unfolded metalloprotein in urea solution. Horse heart cytochrome c (cyt c) has been found to undergo reversible one-electron transfer reactions at pH 2 in the presence of 9 M urea. In contrast, the protein is electrochemically inactive at pH 2 under low-ionic strength conditions in the absence of urea.

The heme iron coordination of unfolded ferric and ferrous cytochrome c in neutral and acidic urea solutions. Spectroscopic and electrochemical studies.

The heme iron coordination of unfolded ferric and ferrous cytochrome c in the presence of 7-9 M urea at different pH values has been probed by several spectroscopic techniques including magnetic and natural circular dichroism (CD), electrochemistry, UV-visible (UV-vis) absorption and resonance Raman (RR). In 7-9 M urea at neutral pH, ferric cytochrome c is found to be predominantly a low spin bis-His-ligated heme center. In acidic 9 M urea solutions the UV-vis and near-infrared (NIR) magnetic circular dichroism (MCD) measurements have for the first time revealed the formation of a high spin His/H(2)O complex.

Crystallographically oriented mesoporous WO3 films: synthesis, characterization, and applications.

Mesoporous semiconducting films consisting of preferentially orientated monoclinic-phase nanocrystals of tungsten trioxide have been prepared using a novel version of the sol-gel method. Transformations undergone by a colloidal solution of tungstic acid, stabilized by an organic additive such as poly(ethylene glycol) (PEG) 300, as a function of the annealing temperature have been followed by means of a confocal Raman microscope. The shape and size of WO3 nanoparticles, the porosity, and the properties of the films depend critically on preparation parameters, such as the tungstic acid/PEG ratio, the PEG chain length, and the annealing conditions.

[Use of principles of iontophoresis and electrophoresis for controlled release of medical substances].

The present review describes work done over the past twenty years on the controlled release of drugs using iontophoresis or electrophoresis techniques. Following a description of therapeutic applications, in vivo and in vitro studies have been discussed with emphasis on the potentials of such techniques to control drug release. Different mathematical models have been reviewed and an attempt has been made to combine them to explain the various configurations of systems currently used.