Quantitative Study of Porosity and Pore Features in Moldavites by Means of X-ray Micro-CT.

X-ray micro-computer aided tomography (μ-CT), together with optical microscopy and imaging, have been applied to the study of six moldavite samples. These techniques enabled a complete characterization to be made of the textural features of both Muong Nong-type and common splashform moldavites. A detailed study of the size and distribution of pores or bubbles confirmed the marked variability in pore size among the samples, as well as within each sample, and indicated in the Muong Nong-type moldavites the presence of at least two deformation stages which occurred before and after pore formation.

Selective electrodesorption based atomic layer deposition (SEBALD): a novel electrochemical route to deposit metal clusters on Ag(111).

The possibility of synergic effects of some metals on the catalytic activity of silver led us to study the way to perform controlled deposition on silver. In fact, many metals of technological interest such as Co, Ni, and Fe cannot be deposited at underpotential on silver, and any attempt to control the deposition at overpotential, even at potentials slightly negative of the Nernst value, did not allow an effective control. However, due to the favorable energy gain involved in the formation of the corresponding sulfides, these metals can be deposited at underpotential on sulfur covered silver.

Cobalt monolayer islands on Ag(111) for ORR catalysis.

The design of a catalyst for one of the most important electrocatalytic reactions, the oxygen reduction reaction (ORR), was done following the most recent guidelines of theoretical studies on this topic. Aim of this work was to achieve a synergic effect of two different metals acting on different steps of the ORR. The catalytic activity of Ag, already known and characterized, was enhanced by the presence of a monolayer of cobalt subdivided into nanosized islands.

In situ scanning tunneling microscopy investigation of sulfur oxidative underpotential deposition on Ag(100) and Ag(110).

Underpotential (UPD) deposition of sulfur from Na(2)S solution in 0.1 M NaOH was studied on Ag(100) and Ag(110) using in situ scanning tunneling microscopy (STM). The cyclic voltammogram on Ag(100) presents two broad peaks, whereas three partial overlapping peaks and a sharper one are observed on Ag(110).

Confined electrodeposition of CdS in the holes left by the selective desorption of 3-mercapto-1-propionic acid from a binary self-assembled monolayer formed with 1-octanethiol.

Confined electrodeposition can be achieved through the use of suitable templates, by which the electrodeposition occurs in natural or artificial holes of an insulating layer on a conducting substrate. Here, we present the electrodeposition of CdS on the holes left by the selective desorption of 3-mercaptopropionic acid (MPA) from a binary self-assembled monolayer (SAM) formed on Ag(111) with 1-octanethiol (OT). The electrodeposition of a compound is quite demanding, since it requires the right stoichiometry.

Nanopatterned Ag substrates for SERS spectroscopy.

Nanopatterned silver substrates with highly reproducible morphologies have been fabricated by micro-contact printing techniques and tested for SERS activity.

Ternary CdSxSe 1-x deposited on Ag(111) by ECALE: synthesis and characterization.

Morphology and electronic properties of CdS, CdSe, and the ternary compounds of formula CdSxSe(1-x) deposited on Ag(111) by ECALE have been characterized as a function of the composition. The number of the attainable x values is limited by the necessity of using well-defined CdS/CdSe deposition sequences. However, the quantitative analysis carried out by XPS and electrochemical stripping experiments indicates that the ECALE method has a good control on composition.

Determination of chlorite in drinking water by differential pulse voltammetry on graphite.

The chlorite ion is an unavoidable by-product of the disinfection of drinking water by means of chlorine dioxide. The maximum concentration values of chlorite accepted in many countries' regulations range from 0.2 to 1.