In situ growth of metallic MoO 2 films on fluorinedoped tin oxide (FTO) and MoO 2 powderi ns olution was achieved simultaneously by as imple hydrothermal process employing citric acid as the surfactant. The growth mechanism of MoO 2 nanostructures (NSs) at the heterogeneousi nterface and in homogeneous mediumproceeds in adifferent manner in which seeds grow in ap referred orientation on FTO, whereas they propagate in all directions in solution. The high lattice matching of FTO and MoO 2 favours the film growth whichc ould not be obtainedo no ther conventional substrates. The disc morphologyo fM oO 2 nanostructures was changed to other diversem orphologyb yv arying the synthesis conditions, particularly by the addition of nitric acid. Ac ompetitive effect of nitric acid and citric acid on the structure direction produced various shapes.T he electrochemicalw ater activation studies showt hat hydrogen-an-nealedM oO 2 is an excellent hydrogen evolution reaction (HER) catalyst with good stability.H -MoO 2 film/FTO displays al ow onset overpotential of72 mV with aT afel slope of 84.1 mV dec À1 ,w hereas the powder form exhibits an onset overpotential of 46 mV with aT afel slope of 71.6 mV dec À1 . The large active surface area, exposure of fringe facets of (110) and the lesser electrochemical charge-transferr esistance offered by the hydrogen-annealed MoO 2 NSsp laya major role in the enhanced HERa ctivity.[a] Dr.

A simple, low cost, two-step synthesis of cobalt oxide nanoparticles sensitized on TiO2 nanorods with enhanced photoelectrochemical properties.

Organic-inorganic hybrids composed of polyfluoroalkyl azobenzene surfactant (abbreviated as C3F-Azo-C6H) and inorganic layered compounds are able to undergo reversible three-dimensional morphology changes such as interlayer space changes and nanosheet sliding in a giant scale due to reversible trans-cis isomerization of the azobenzene moiety upon photo-irradiation. In this paper, we have systematically studied the relationship between the layered hybrid microstructures of C3F-Azo-C6H-clay and their photoreactivity for understanding the mechanism of the photo-induced morphology change. The photoreactivity was found to be very much affected by the surrounding microenvironments. As compared with it in solution, the cis-trans photo-isomerization in C3F-Azo-C6H-clay nano-layered film was substantially enhanced with the quantum yield exceeding unity (Φ = 1.9), while the trans-cis isomerization was rather retarded. The corresponding hydrocarbon analogue of the azobenzene surfactant (C3H-Azo-C6H) did not show such an enhancement. The enhancement was discussed in terms of a cooperative effect among adjacent azobenzene moieties along with polyfluoroalkyl chains and the inorganic clay nanosheet to prevent a dissipation of the excess energy being liberated during the photo-isomerization within the nano-layered microenvironment.

We present results of applied field nonequilibrium molecular dynamics simulations (AF NEMD) of a minimal beta-barrel model channel intended to represent an L-type calcium channel that suggests a possible relationship between glutamate side chain conformational changes and ion flux in calcium channels. The beta-barrel is used to provide a scaffolding for glutamate side chains and a confinement for electrolyte of dimensions similar to the expected channel structure. It was preloaded with ions to explore relative rates of ion exit for different occupancy configurations. Our simulations with an asymmetrical flexible selectivity filter represented by four glutamate side chains (EEEE), one of which differs in initial dihedrals from the other three, indicate a plausible mechanism for the observed anomalous mole fraction effect seen in calcium channels. Apparent rates of electric field-induced exit from channels preloaded with three Na+ ions are much higher than for channels with one Ca2+ followed by two Na+ ions, consistent with the common notion that Ca2+ block of Na+ current is due to competition between the Ca2+ and Na+ ions for the negatively charged (EEEE) locus. In our model, the Ca2+ ion ligates simultaneously to the four negatively charged glutamate side chains and sterically blocks the permeation pathway. Ca2+-relief of Ca2+-block is suggested by a much higher rate of exit for channels preloaded with three Ca2+ ions than for channels with two Ca2+ ions.

Hematite (α-Fe 2 O 3 ) is one of the most studied photoanode materials due to its stability in alkaline electrolytes and visible light absorption. However, its reported performance lags significantly behind its theoretical limit. Toward determining routes for efficient photo-oxidation on hematite, we investigated the role of hole-trapping surface states as reaction intermediates using sacrificial reductant reagents as hole scavengers, H 2 O 2 and FeCN. Photoelectrochemical characterization at low scavenger concentrations and intermediate potentials, as opposed to previous studies at high scavenger concentrations, has shown the reaction mechanism to include competitive photo-oxidation between water molecules and the hole scavengers, similar for both H 2 O 2 and FeCN. Using operando Raman spectroelectrochemistry, we show similar transient features for both scavengers, interpreted as scavenger adsorption to a two-site reaction intermediate participating in the photogenerated hole transfer of water photo-oxidation, hence the competition. These findings strengthen the significance of hole-trapping surface states for water photo-oxidation on hematite and the previously suggested two-site reaction pathway for efficient hole transfer in this reaction. A better understanding of the mechanisms of photoelectrochemical water splitting can assist in improving the efficiency of solar hydrogen production.