Mesoscopic oxide

Dye-Sensitized Solar Cells Based on Mesoscopic Oxide Semiconductor Films... 

Preparation and morphology of mesoscopic oxide semiconductor films... 

Consider a 10-pm thick mesoscopic oxide film composed of 20-nm-sized particles whose real surface area is over 1,000 times greater than the projected one. Because of the small size of the particles such films show high transparency and negligible... 

The electron motion in the conduction band of the mesoscopic oxide film is coupled with interfacial electron-transfer reaction and with ion diffusion in the electrolyte. Bisquert [51] has introduced a transmission line description to model these processes. The mesoscopic film is thought to be composed of a string of oxide nanoparticles (Fig. 12). Apart from recapture by the oxidized dye, the electrons can... 

The semiconductor nanoparticle most commonly used is the anatase form of Ti02 however, other mesoscopic oxides can also be used, such as Sn02, ZnO, Nb20s, WO3, and Ta20s. Dye molecules are chemisorbed onto the semiconductor (Fig. 6b), forming close to a monolayer. This dye-semiconductor assembly is arranged over a transparent conducting oxide and the set is put into contact... 

Bisquert, J., Gratzel, M., Wang, Q., Fabregat-Santiago, F. Three-channel transmission line impedance model for mesoscopic oxide electrodes functitmalized with a conductive coating. J. Phys. Chem. B 110, 11284-11290 (2006)... 

Wang Q, Zakeeruddin SM, Nazeeniddin MK, Hxmiphry-Baker R, Gratzel M (2006) Molecular wiring of nanocrystals NCS-enhanced cross-surface charge transfer in self-assembled Ru-complex monolayer on mesoscopic oxide films. J Am Chem Soc 128 4446-4452... 

The autocatalytic reaction mechanism apparent at low temperatures is expected to apply to catalytic hydrogen oxidation at high pressures. In addition, the above study is the first to use STM to observe the formation of dynamic surface patterns at the mesoscopic level, which had previously been observed by other imaging techniques in surface reactions with nonlinear kinetics [57]. This study illustrates the ability of in situ STM to visualize reaction intermediates and to reveal the reaction pathway with atomic resolution. 

A. Duret, M. Gratzel, Visible light-induced water oxidation on mesoscopic a-Fe203 films made by ultrasonic spray pyrolysis, J. Phys. Chem. B 109 (2005) 17184-17191. 

Czuryszkiewicz T, Rosenholm J, Kleitz F, Linden M (2002) Synthesis and characterization of mesoscopically ordered surfactant/cosurfactant templated metal oxides. Impact of Zeolites and Other Porous Materials on the New Technologies at the Beginning of the New Millennium, Book Series Studies in Surface Science and Catalysis, Pts A and B 142 1117-1124... 

A more recent trend in polymer materials research is the hybridization of cellulosic polysaccharides with inorganic compounds natural and synthetic layered clays, silica, zeolites, metal oxides, and apatites are employable as nanoscale components. In addition, if mesoscopic assemblies such as liquid-crystalline ordering are used in the construction of new compositional systems, the variety of functionalized cellulosic materials will be further expanded. 

There are some unique examples of organic-inorganic hybrids in natural systems. Some kinds of protein possess inorganic components at their interior. Because such bio-originated hybrid structures have discrete size and composition, they can be used for preparation of fine mesoscopic structures. For example, ferritin, which is composed of 24 self-assembled peptide subunits and capable of including iron oxide, is a good candidate to fulfill this demand. Yamashita demonstrated use of a ferritin array for preparation of a mesoscopic nanodot array (Fig. 2.11 ).47 A Langmuir... 

K. Shabtai, S. R. Cohen, H. Cohen, and I. Rubinstein, A Composite Gold-Silicon Oxide Surface for Mesoscopic Patterning, J. Phys. Chem. B 107, 5540-5546 (2003). 

Reactions that occur between components in the bulk solution and vesicle-bound components, i.e., reactions occurring across the membrane interface, can be treated mathematically as if they were bimolecular reactions in homogeneous solution. However, kinetic analyses of reactions on the surface of mesoscopic structures are complicated by the finiteness of the reaction space, which may obviate the use of ordinary equations of chemical kinetics that treat the reaction environment as an infinite surface populated with constant average densities of reactant molecules. As was noted above, the kinetics of electron-transfer reactions on the surface of spherical micelles and vesicles is expressed by a sum of exponentials that can be approximated by a single exponential function only at relatively long times [79a, 81], At short times, the kinetics of the oxidative quenching of excited molecules on these surfaces are approximated by the equation [102]... 

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