Federico Napolitano

Metal oxides: crystallographic characterizations for high-temperature electrochemistry applications

The strong relationship between the crystallographic structure and defects with the electronic and transport properties of a certain material is a key figure in most of the research conducted in materials science. The properties of an oxide in particular (transport, electrochemical, thermal, etc.) can be affected by several factors including the synthesis method and environmental conditions such as pressure, temperature, atmosphere, electrical current and field, magnetic field, etc. Therefore, it is important to go beyond the limited information obtained through the traditional ex-situ characterization techniques toward the more exhaustive ones provided by the in-situ or in-operando experiments, where it is possible the study of a device under nonambient working conditions.

Synthesis and characterization of cobaltite nanotubes for solid-oxide fuel cell cathodes

La1-xSrxCo1-yFeyO3-? oxides are good candidates for solid oxide fuel cell (SOFC) cathodes because these materials present high ionic and electronic conductivity, and compatibility with Cerium Gadolinium Oxide (CGO) electrolytes allowing a lower operation temperature. In this work, we report the synthesis of La0.4Sr0.6Co0.8Fe0.2O3-? (LSCF) nanotubes prepared by a porous polycarbonate membrane approach, obtaining different microstructures depending on sintering conditions. The structure and morphology of the nanotubes and deposited films were characterized by X-ray diffraction, transmission and scanning microscopy. Finally, we obtained nanostructured films of vertically aligned LSCF tubes deposited over the whole surface of CGO pellets with diameter up to 2.5cm in a direct and single step process.