Diatom frustules enhancing the efficiency of gel polymer electrolyte based dye-sensitized solar cells with multilayer photoelectrodes

The incorporation of nanostructures that improve light scattering and dye adsorption has been suggested for dye-sensitized solar cells (DSSCs), but the manufacture of photonic and nanostructured materials with the desired properties is not an easy task. In nature, however, the process of light-harvesting for photosynthesis has, in some cases, evolved structures with remarkable wavelength-sensitive light-trapping properties. The present work is focused on enhancing the efficiency of quasi solid-state DSSCs by capitalizing on the light trapping properties of diatom frustules since they provide complex 3-dimensional structures for scattering and trapping light. This study reports a promising approach to prepare TiO2 nanocrystal (14 nm) based photo-electrodes by utilizing the waveguiding and photon localization effects of nanostructured diatom frustules for enhancing light harvesting without deteriorating the electron conduction. Single and double-layered photo-electrodes were prepared with different frustule/nanocrystal combinations and conformations on transparent conductive oxide substrates. This study clearly reports impressive efficiency and short circuit current density enhancements of about 35% and 39%, respectively, due to the incorporation of diatom frustules extracted from a ubiquitous species. The SEM images obtained in this work reveal that the produced thin films had a remarkable surface coverage of evenly distributed frustules within the TiO2 nanoparticle layer. To the best of our knowledge, this study reports the first quasi solid-state DSSC based on a photo-electrode with incorporated bio-formed nanostructures

Notulae to the Italian alien vascular flora: 11

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1

Studi conduttometrici, vibrazionali e di luminescenza in elettroliti polimerici

Dottorato di ricerca in scienze chimiche. 8. ciclo. Supervisore M. VidaliConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Conductivity, luminescence and vibrational studies of the poly(ethylene glycol) 400 electrolyte based on Europium trichloride.

Poly(ethylene glycol) 400/(EuCl3)(x) electrolytic complexes with 0 less than or equal to x less than or equal to 0.327 were prepared. The ionic conductivity of these systems was investigated, and the data were satisfactorily well fitted by the empirical Vogel-Tamman-Fulcher equation. Two different conductivity regions depending on the electrolytic complexes compositions were observed. The conformation of the poly(ethylene glycol) 400 (PEG 400) in the complexes was investigated by FT-IR and Raman spectroscopies. These investigations suggest that the PEG 400 chains in PEG 400/(EuCl3)(x) present a TGT conformation (T = trans, G = gauche). Moreover, by laser luminescence spectroscopy it was also proved that each Eu3+ ion is coordinated by four oxygen atoms of PEG in a distorted C-2v site symmetry