Search results for "O2"

Phosphomolybdic Acid and Mixed Phosphotungstic/Phosphomolybdic Acid Chitosan Membranes for H2/O2 Fuel Cells

2016

Proton exchange membrane fuel cells (PEMFCs) have received much attention in recent years because of their high power density, efficiency and zero-environmental pollution. As one of the key components in fuel cells, the proton exchange membrane is expected to have high proton conductivity and good electrochemical stability. In the attempt to promote PEMCFs commercialization, high cost of fuel cell systems and short lifecycle are the two main issues that need to be addressed, thus large research effort has been devoted in developing new polymer electrolytes that can replace the usually employed proton conductors, e.g. Nafion®, with other membranes of comparable performances but lower cost. A…

Silicate and Hydroxide Concentration Influencing the Properties of Composite Al2O3-TiO2 PEO Coatings on AA7075 Alloy

2021

This work evaluates the effect of sodium meta-silicate pentahydrate (SMS) and potassium hydroxide concentrations on properties of Al2O3-TiO2 coatings produced through plasma electrolytic oxidation in a solution containing 3 g L−1 potassium titanyl oxalate, (PTO), using a unipolar waveform with constant current density. The surface and cross-section characteristics of PEO coatings including morphology, elemental distribution, and phase composition were evaluated using FESEM, EDS, and XRD techniques. Voltage-time response indicated the concentration of SMS and KOH had a significant effect on the duration of each stage of the PEO process. More cracks and pores were formed at the higher concent…

Redshift of absorption threshold of TiO2 Nanotubes due to Cu2O electrodeposition

2013

Resistive switching of anodic TiO2-based Memristors

2018

In recent years, memristors have attracted great attention owing to their simple fabrication process, high scalability, good compatibility with the CMOS technology, high switching speed, low power consumption and low cost for next-generation non-volatile memory technology [1]. The basic cell structure of a memristor is an insulator sandwiched between two metal electrodes. Among the materials being studied for memristors fabrication, binary metal oxides, such as TiO2, are most favourable because of their simple constituents, compatible with CMOS processes, and resistive to thermal/chemical damages. Anodizing is a an electrochemical low cost process carried out at room temperature to grow oxi…

Pulsed laser deposition of ZnO and VO2 films for memristor fabrication

2015

Memristors are resistive switching memory devices which have attracted much attention over the last years for high-density memory applications because of their simple structure, small cell size, high speed, low power consumption, potential for 3-D stacking and excellent compatibility with the complementary metal-oxide-semiconductor (CMOS) technology [1]. Beside nonvolatile memory applications, memristors have been also proposed for other different applications including biosensors [2] and neuromorphic [3] circuits. The device structure is simply an oxide material sandwiched between two metal electrodes. The switching behavior is not only dependent on the oxide material but also on the choic…

An Electrochemical Investigation on the Adhesion of As-Formed Anodic TiO2 Nanotubes Grown in Organic Solvents

2011

Accumulo e conversione di energia per via elettrochimica attraverso batterie piombo-acido con elettrodi nano-strutturati

L’attività di ricerca si è focalizzata sullo studio delle batterie al piombo acide, largamente utilizzate nel campo della trazione e dell’accumulo di energia da fonti rinnovabili. La loro grande limitazione è legata al peso, intrinsecamente dovuto all’alto peso molecolare del piombo stesso, e al basso grado di utilizzazione del materiale attivo, che non le rendono competitive in altri possibili ambiti come la trazione elettrica o in dispositivi portatili. Per superare questa limitazione l’approccio è stato quello di rendere porosa la materia attiva mediante l’uso di array ordinati di nanostrutture ottenute per elettrodeposizione; mediante l’uso di uno stampo, è possibile ottenere elettrodi …

Influence of heteropolyacid in enhancing proton conductivity of chitosan membranes for H2/O2 Fuel Cells

2016

To promote Proton Exchange Membrane Fuel Cells (PEMFCs) commercialization, large research effort has been devoted in developing new polymer electrolytes that can replace the usually employed proton conductors, e.g. Nafion®, with other membranes of comparable performances but lower cost. Chitosan (CS)-based membrane electrolyte is currently studied as alternative candidate for PEMFC application. Several works have shown that Heteropolyacids (HPAs) can be used to prepare Chitosan polyelectrolytes (PECs) to be employed as proton exchange membrane in low temperature fuel cell. In previous works [1-3] we have shown that CS/PTA membranes, prepared using alumina porous medium for the slow release …

Performance analysis of nanostructured PbO2 electrodes in lead-acid batteries

2013

Photocatalysis in dimethyl carbonate green solvent: degradation and partial oxidation of phenanthrene on supported TiO2

2014

Dimethyl carbonate (DMC) is here proposed – for the first time – as a green organic solvent for photocatalytic synthesis. In this work, the photocatalytic partial oxidation of phenanthrene in dimethyl carbonate (DMC) by using anatase TiO2 as the photocatalyst is described as paradigmatic example of a green synthetic process starting from polycyclic aromatic hydrocarbons (PAHs). For comparison, the same reaction carried out also in ethanol, 1-propanol or 2-propanol is reported. The use of DMC as the solvent allowed us to achieve 19% and 23% selectivity towards 9-fluorenone and 6H-benzo[c]chromen- 6-one, respectively. The proposed approach may represent both a new green synthetic process and …