Hydrothermally Processed Oxide Nanostructures and Their Lithium–ion Storage Properties

Y- and Si-based oxide nanopowders were synthesized by a hydrothermal reaction of Y or Si powders with NaOH or LiOH aqueous solution. Nanoparticles with different morphology such as elongated nanospheres, flower-like nanoparticles and nanowires were produced by a control of processing parameters, in particular, the starting composition of solution. The preliminary result of electrochemical examination showed that the hydrothermally processed nanowires exhibit high initial capacities of Li-ion storage: 653 mAh/g for Y2O3 nanowires as anode materials and 186 mAh/g for Li2Si2O5 nanowires as cathode materials in a Li secondary cell. Compared to the powder with elongated sphere or flower-like shapes, the nanowires showed a higher Li-ion capacity and a better cycle property

Electron Transfer form Organic Aminophenyl Acid Sensitizers to Titanium Dioxide Nanoparticle Films

none5P. Myllyperkio; C. Manzoni; D. Polli; G. Cerullo; J. Korppi-TommolaP., Myllyperkio; Manzoni, Cristian; Polli, Dario; Cerullo, GIULIO NICOLA; J., Korppi Tommol

Photoinduced interfacial electron injection in RuN3-TiO2 thin films: Resolving picosecond timescale injection from the triplet state of the protonated and deprotonated dyes

Using femtosecond transient absorption spectroscopy we have studied light-induced electron injection from the sensitizer RuN3 and its partly deprotonated tetrabutylamonium salt to nano-structured TiO2 film. Previous studies have suggested significant differences in electron injection dynamics for these dyes and some results have indicated that aggregation of the sensitizer may lead to slow injection. By measuring transient absorption spectra and kinetics of RuN3 and RuN3-TBA in solution and attached to TiO2 film we show that the electron injection dynamics are very similar for the two forms of the dye and that aggregation has only moderate effects on the electron transfer dynamics. (c) 2008 Elsevier B. V. All rights reserved