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ZnO film was prepared from 0.1moldm−3 zinc nitrate aqueous solution by the potentiostatic technique using a three-electrode system at 313–343K . The ZnO film was characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. In addition, measurements of interface pH and electrochemical quartz crystal microbalance (EQCM) during the electrodeposition were carried out to elucidate the deposition mechanism. It was disclosed that the deposition scheme at the initial stage is quite different depending on bath temperature. The change in deposition mechanism with temperature is closely related to the increased thermodynamic stability of ZnO at high temperature. Based on EQCM analysis, it was suggested that the precursor of ZnO is slowly transformed to ZnO at low temperature, but the formation of ZnO is extremely rapid at high temperature, i.e., ZnO directly deposits at high temperature. Auger analysis indicated that transition from the precursor to ZnO crystal started from the bottom to the surface when the amount of precursor became larger than a critical value depending on temperature.

Ag nanoparticle catalysts were prepared to replace the Pd/Sn catalysts for electroless Cu plating. Suspensions of Ag nanoparticles, of which the average diameter was 4.6 nm, were obtained instantaneously by mixing a AgNO3 solution and a Sn(II)–citrate complex solution at a nearly neutral pH. The composition and electron diffraction patterns of the nanoparticle as well as a high stability of the suspensions suggested that the nanoparticles have the core-shell structure composed of the metallic Ag core surrounded by the SnO2 shell. The adsorption of Ag nanoparticles onto the epoxy substrates was promoted by conditioning the substrate with alkyltrimethylammonium chloride (ATA) having an alkyl tail longer than C16. A small amount of Sn was also adsorbed. The promotion of the Ag nanoparticle adsorption can be accounted for by the large amount of adsorbed surfactant due to the hydrophobic interaction with the substrate. The positively charged ATA adsorbates acted as an electrostatic glue to adsorb the negatively charged Ag nanoparticles. Electroless Cu deposition was started at the epoxy substrates catalyzed with Ag nanoparticles.

In the chemical ZnO deposition on Pd-catalyzed glass from aqueous dimethylamineborane ͑DMAB͒ solutions, effects of counteranions ͑NO 3 − , Cl − , ClO 4 − , and SO 4 2− ͒ and dissolved oxygen ͑DO͒ on the hydrolysis behavior of Zn 2+ and the growth regime of ZnO were studied using sodium and zinc salt solutions bubbled with O 2 , air, or Ar gas. The interaction of the counteranions with H + and Pd as well as Zn 2+ was suggested as an important factor for the chemical ZnO deposition, and it was found that only NO 3 − can raise the pH of a DMAB solution without DO, affording the continuous ZnO growth. Dissolved oxygen accelerated the ZnO nucleation process on the Pd and had less influence comparable to NO 3 − on the subsequent growth on the ZnO surface. The ZnO films deposited from Zn͑NO 3 ͒ 2-DMAB solutions bubbled with O 2 , air, or Ar gas were characterized with an X-ray diffractometer, field emission scanning electron microscope, UV-visible spectrophotometer, and Hall coefficient analyzer. The Ar-bubbled solution gave superior ZnO films in terms of crystallinity, growth orientation, surface morphology, and electrical conductivity due to the relatively moderate crystal nucleation compared to in the presence of DO.

We focus on the proton-conducting doped -barium zirconate, which has large proton conductivity at intermediate temperature.We found here a phenomenon that acid -etching of the doped barium zirconate in a solution having a specific pH leaves a porous structure on the surface, and demonstrated power generation of hydrogen fuel cell using electroless-plated Pd and Pt on the porously acid-etched electrolyte surface. The short circuit current density of the hydrogen fuel cell was about 430 mA/cm 2 at 600 C using thick electrolyte of 500 m.A secondary battery is considered to be used to level off power generation using natural resources, but it is expensive and a finite battery capacity limits the amount of stored electrical energy; however, if we use fuel as a storing medium for electricity, huge electricity can be stored. Fuel cells are one of the most developed devices for the conversion from fuel to electricity and vice versa. Among them, proton conductor fuel cells have an advantage over oxide ion conductor fuel cells because hydrogen generation in steam electrolysis occurs on another electrode to which steam is fed, which allows high utilization of the fed steam or operation at moderate overpotential in the whole area of the anode. A similar advantage can be recognized in power generation in hydrogen fuel cell operation; that is, the utilization of hydrogen fuel is expected to be higher. A fuel cell using high temperature proton-conducting oxide, 1 called in the literature PCFC (Protonic Ceramic Fuel Cell), 2,3 has several benefits over PEMFC(Polymer Electrolyte Membrane Fuel Cell) because PCFC can be operated in an intermediate temperature range of 400-600 C to allow to the use of inexpensive catalysts. Representative proton-conducting ceramics are trivalent cation-doped barium zirconates or cerates. 4-6 These have the highest class conductivity at intermediate temperature among the ceramic ionic conductors. 7,8 Doped barium zirconates are relatively stable even in an atmosphere containing carbon dioxide, although doped barium cerates decompose by carbon dioxide. 9 So far, most research on fuel cells using proton-conducting ceramics has focused on doped barium cerates because they were discovered first and making dense electrolyte was easier. Many successful investigations on electrode material for doped barium cerates or solid solutions of zirconate and cerate have been reported. 10-13 But when applying the same strategy for electrode materials to doped barium zirconates, No attempts have obtained satisfactory results. [13][14][15] In our study of an electroless-plating method for yttrium-doped barium zirconate(BZY) we incidentally found that porous structure could be made by just immersing the pellet of BZY in an acid solution at room temperature. This is a quite interesting and useful phenomena to improve the electrode performance of doped barium zirconates. We here introduce this unique approach in detail. ExperimentalCrystalline powders of 20% yttrium-doped barium zirconate were prepared by a solid state re...

A cerium dioxide (CeO 2 ) film with characteristic cubic lattice and optical band gap energy has been deposited chemically onto a non-conductive glass substrate at 333 K by simple immersion into an aqueous solution containing hydrous cerium(III) nitrate and dimethylamineborane (DMAB).

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