Publications by authors named "Celso M Aldao"
Article Synopsis
- CeO samples were made using the polymeric precursor method with varying calcination temperatures, leading to changes in particle size and shape.
- Advanced techniques like positron annihilation lifetime spectroscopy (PALS) and electron paramagnetic resonance (EPR) revealed the presence of different types of oxygen vacancies associated with various cerium ions.
- Impedance spectroscopy showed that as the calcination temperature increased, there was a reduction in electrical conductance and the formation of polarons in the material.
The adsorption of oxygen and its reaction with target gases are the basis of the gas detection mechanism by using metal oxides. Here, we present a theoretical analysis of the sensor response, within the ionosorption model, for an n-type polycrystalline semiconductor. Our goal of our work is to reveal the mechanisms of gas sensing from a fundamental point of view.
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- The study examined the electrical properties of β-AgMoO materials, focusing on both Eu-doped and undoped versions synthesized via microwave-assisted hydrothermal methods.
- It found that the synthesis time affects defect concentrations, particularly silver vacancies (V), showing that Eu doping initially boosts V concentration but leads to a decrease over time.
- The research employed various analytical methods, like photoluminescence and impedance spectroscopy, to develop a comprehensive understanding of the conduction mechanisms in these materials.
In the original paper, Zhao and co-workers describe a sensing model to explain the response to a reducing gas as a function of the oxygen partial pressure. In this Comment we specifically analyze the basic gas detection mechanisms proposed in such a work and expressed through surface reactions (eqs 1-5). The consequence of these presented mechanisms lead to inconsistencies that are also regularly found in the literature.
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