Ricerc@Sapienza

A synergic approach combining X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies together with quantum mechanical (QM) calculations on cluster models has been used to investigate the solvation properties of the HgCl2 salt and of HgO dissolved in deep eutectic solvents (DESs). Choline chloride (ChCl)-based DESs were prepared using different hydrogen bond donors, namely 1:2 mixtures of ChCl and either urea, acetylsalicylic acid (ASA) or sesamol (SES) and a 1:1 mixture of ChCl and pyrogallol (PYR).

Fe3O4 nanoparticles synthesized by a base catalyzed method are tested in an All-Solid-State (ASLB) battery using a sulfide
electrolyte. The pristine nanoparticles were morphologically characterized showing an average size of 12 nm. The evaluation of the
electrochemical properties shows high specific capacity values of 506 mAhg−1 after 350 cycles at a specific current of 250 mAg−1,
with very high stability and coulombic efficiency.

Preparing an anatase TiO2(101) surface with a high density of oxygen vacancies and associated reduced Ti species in the near-surface region results in drastic changes in the water adsorption chemistry compared to adsorption on a highly stoichiometric surface. Using synchrotron radiation excited photoelectron spectroscopy, we observe a change in the water growth mode, from layer-by-layer growth on the highly stoichiometric surface to bilayer growth on the reduced surface. Furthermore, we have been able to observe Ti3+ enrichment at the surface upon water adsorption.

The anatase TiO2(101) surface and its interaction with water is an important topic in oxide surface chemistry. Firstly, it benchmarks the properties of the majority facet of TiO2 nanoparticles and, secondly, there is a controversy as to whether the water molecule adsorbs intact or deprotonates. We have addressed the adsorption of water on anatase TiO2(101) by synchrotron radiation photoelectron spectroscopy. Three two-dimensional water structures are found during growth at different temperatures: at 100 K, a metastable structure forms with no hydrogen bonding between the water molecules.