Photoelectrochemical Behavior of Electrophoretically Deposited Hematite Thin Films Modified with Ti(IV).

Doping hematite with different elements is a common strategy to improve the electrocatalytic activity towards the water oxidation reaction, although the exact effect of these external agents is not yet clearly understood. Using a feasible electrophoretic procedure, we prepared modified hematite films by introducing in the deposition solution Ti(IV) butoxide. Photoelectrochemical performances of all the modified electrodes were superior to the unmodified one, with a 4-fold increase in the photocurrent at 0.

Microbial deterioration of artistic tiles from the façade of the Grande Albergo Ausonia & Hungaria (Venice, Italy).

The Grande Albergo Ausonia & Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made.

An Experimental and Theoretical Study of the Electronic Structure of Zinc Thiophenolate-Capped Clusters.

The electronic structure of a series of thiophenolate-capped ionic/neutral clusters ([Zn(SPh)(4)](2)(-) (1); [Zn(4)(&mgr;(2)-SPh)(6)(SPh)(4)](2)(-) (2); Zn(10)(&mgr;(3)-S)(4)(&mgr;(2)-SPh)(12) (3); and [Zn(10)(&mgr;(3)-S)(4)(&mgr;(2)-SPh)(12)(SPh)(4)](4)(-) (4), Ph = phenyl), indicated as supertetrahedral fragments and possible molecular models of cubic ZnS, has been investigated by coupling density functional calculations to UV electronic and X-ray photoelectron (XP) spectroscopy. Theoretical outcomes indicate that, on passing from the tetrametallic to the decametallic clusters, there is a modification in the nature of the outermost occupied and lowermost unoccupied molecular orbitals. Actually, both in 1 and in 2 the frontier orbitals are delocalized and mainly composed of the S 3p pairs strongly mixed with the Ph pi levels (the HOMOs) and of the linear combinations of Ph pi orbitals, the LUMOs.