S. Trocino

Oxygen-sensing properties of electrospun CNTs/PVAc/TiO2 composites

Multi-walled-carbon-nanotubes/polyvinylacetate/titanium oxide (MWCNTs/PVAc/TiO2) composite fibers with different MWCNT loadings were prepared using the electrospinning technique. The addition of cetyl trimethyl ammonium bromide (CTAB) as a surfactant agent to promote the dispersion of the MWCNTs was also evaluated. The morphological and microstructural properties of as-spun and annealed samples in air at 600°C were examined using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The sensing characteristics of the synthesized TiO2-based nanostructures were evaluated for oxygen monitoring at moderate temperatures. The effects of the MWCNT loading, the addition of the surfactant and the composition of the TiO2 crystalline phases were investigated and discussed.

Nickel–Iron/Gadolinium-Doped Ceria (CGO) Composite Electrocatalyst as a Protective Layer for a Solid-Oxide Fuel Cell Anode Fed with Biofuels

The performance and reliability of a commercial solid‐oxide fuel cell (SOFC) with the anode coated by a protective catalytic layer is demonstrated. Physico‐chemical and electrochemical characterizations of a Ni–Fe/gadolinium‐doped ceria (CGO) electrocatalyst forming the protective layer are reported. The anode layer was prepared by using a procedure that favors the interaction between Ni and Fe. Power densities approaching 0.3 W cm−2 for the SOFC cell fed with dry organic fuels were obtained. A time test was performed in the presence of a large flow rate of dry organic fuels under operating conditions (0.8 V) showing appropriate fuel flexibility for the device. The resistance to sulfur contamination was verified by feeding increasing amounts of H2S. The cell showed only moderate performance losses until 80 ppm of sulfur contaminant.

Electrochemical Impedance Spectroscopy as a Diagnostic Tool in Polymer Electrolyte Membrane Electrolysis

Membrane–electrode assemblies (MEAs) designed for a polymer electrolyte membrane (PEM) water electrolyser based on a short-side chain (SSC) perfluorosulfonic acid (PFSA) membrane, Aquivion®, and an advanced Ir-Ru oxide anode electro-catalyst, with various cathode and anode noble metal loadings, were investigated. Electrochemical impedance spectroscopy (EIS), in combination with performance and durability tests, provided useful information to identify rate-determining steps and to quantify the impact of the different phenomena on the electrolysis efficiency and stability characteristics as a function of the MEA properties. This technique appears to be a useful diagnostic tool to individuate different phenomena and to quantify their effect on the performance and degradation of PEM electrolysis cells.

UV Effect on Indium Oxide Resistive Sensors

In this paper, electrospinning technique has been employed to synthesize In2O3/PVP (indium oxide/polyvinylpyrrolidone) composite fibers. The produced In2O3 fibers after annealing at 600 °C were investigated as sensitive layer in resistive sensors for monitoring NO2 at low concentrations in air. By optimizing the spinning conditions and the subsequent annealing treatment, In2O3 fibers have been successfully obtained. The annealed samples have a high crystallization degree. Their sensing behavior towards nitrogen dioxide has been then tested both in the dark and under UV light. To analyze in detail the effect of UV radiation, sensing tests have been performed by using three different procedures: without UV illumination, under continuous UV illumination, and under pulsed UV illumination (provided only during the recovery time). It has been proved that the optimal sensing characteristics (higher sensibility and very shorter recovery time) of the sensor occur when the sample is irradiated with pulsed UV light.