Porous nanostructure

Ordered Porous Nanostructures and Applications Edited by RalfWehrspohn... 

Vanmaekelbergh D, de Jongb PE (1999) Driving force for electron transport in porous nanostructured pbotoelectrodes. J Pbys Cbem B 103 747-750... 

In order to take advantage of nanometer-sized semiconductor clusters, one must provide an electron pathway for conduction between the particles. This has been achieved by sintering colloidal solutions deposited on conductive glasses. The resulting material is a porous nanostructured film, like that shown in Fig. 1, which retains many of the characteristics of colloidal solutions, but is in a more manageable form and may be produced in a transparent state. Furthermore, the Fermi level within each semiconductor particle can be controlled potentiostati-cally, a feature which is fundamental for the functioning of the electrochromic devices described in Section III. 

For different electrochemical applications such as batteries, supercapacitors, fuel elements porous carbon nanomaterials are used. We have obtained porous carbon nanofibers by CVD method from acetylene with use of new (Fe,Co,Sn)/C/Al203-Si02 catalysts prepared by mechanochemical method [13, 14]. The porous nanostructures formed (Fig. 4) somewhat resembles structures, synthesized in [15] on titania-containing catalyst. 

It must have a porous nanostructure that allows a fast transport of protons (generated from water oxidation) to the underlying proton-conductive membrane, avoid surface recombination between protons and electrons (which should have different paths of transport), and have an optimal interface with the membrane. 

Driving force for electron transport in porous nanostructured photoelectrodes. D. Vanmae-kelbergh and P. E. de Jongh, J. Phys. Chem. B, 103, 747 (1999). 

The electrochemical reduction of platinum sails confined to the aqueous environments of lyotropic liquid-crystalline phases leads to the deposition of platinum films[262] that have a well defined long-ranged porous nanostructure and high specific surface areas. These results suggest that the use of liquid-crystalline plating solutions could be a versatile way to create mesoporous electrodes for batteries, fuel cells, electrochemical capacitors, and sensors. 

Antonio Domenech holds a Ph.D. in chemistry (University of Valencia, 1989) and is currently professor in the Department of Analytical Chemistry, University of Valencia, Spain. His research is focused on supramolecular electrochemistry, electrochemistry of porous nanostructured materials, and electroanalytical methods applied to conservation and restoration of cultural heritage, as well as on educational problems in teaching of science. He has published more than 150 articles in scientific journals and several monographs, among them Supramolecular Chemistry of Anions and Electrochemical Methods in Archeometry, Conservation and Restoration. Dr. Domenech received the Demetrio Ribes award for original research (Valencian Regional Government) in 2006. 

Thin films of nanostructured metals and semiconductors (e.g., Pt, Sn, CdTe) can be prepared by electrodeposition of the metal ions doped into the Hi LLC phase [40,47,48]. Similar to the precipitation of CdS, these films can retain the symmetry of the LLC template during the deposition. These materials allow one to combine well-defined porous nanostructures, high specific surface areas, electrical connectivity, fast electrolyte diffusion, and good mechanical and electrochemical stability. With this approach, hexago-nally structured semiconductor films of uniform thickness can be prepared. Nanostructured thin films of this type are proposed to have relevance in catalysis, batteries, fuel cells, capacitors, and sensors. 

Fig. 19. Various possibilities for templating materials into solid, hollow and porous nanostructures...

We developed an approach for analysis of reflectance spectra with bands of interference origin, for thin porous nanostructured layers on silicon wafers and made the automatic reflectometry equipment to examine optical characteristics (reflectance coefficient, refractive index) in the visible, near- infrared and mid- infrared range. The method is applied to por-Si, por-CoSi2 and por-A Os layers on c-Si substrate. The reflectance spectra, recorded at different light incidence angles permit to detect both the refractive index and layer thickness simultaneously. TEM, AFM, IR spectroscopy investigations of these layers confirmed the presence of Si nanocrystals. 

In this paper we present research on SILD technology for deposition of the mentioned above porous nanostructured SnOz layers. Last years the SILD technology excites high interest, because this method of metal oxide deposition is simple, inexpensive, and gives possibility to deposit thin nanostructured films on rough surfaces [1]. 

One of the targets in the formation of 2D porous nanostructures is to define and control the size of the cavities. The obvious approach is to extend the distance between the carboxylic acid groups and the center of the molecule, for instance by a phenyl group. 1,3,5-Benzenetribenzoic acid (BTB) is a rigid molecule and self-assembles also at the liquid-solid interface into honeycomb-type networks (Fig. 21 A) [55]. The circular cavities have a diameter of about 2.8 nm. In case of TMA, the cavity diameter is about 1 nm only. 

This paper shortly reviews the recent results on development of new sol-gel protective coatings with different kinds of nanocontainers loaded with corrosion inhibitors. The oxide nanoparticles, the porous nanostructured layers and the... 

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