Artículos SCI

In this article we show for the first time the formation of magnetic supported organic nanowires (ONWs) driven by self-assembly of a nonplanar Fe(III) phthalocyanine chloride (FePcCl) molecule. The ONWs grow by a crystallization mechanism on roughness-tailored substrates. The growth methodology consists of a vapor deposition under low vacuum and mild temperature conditions. The structure, microstructure, and chemical composition of the FePcCl NWs are thoroughly elucidated and compared with those of Fe(II) phthalocyanine NWs by a consistent and complementary combination of advanced electron microscopies and X-ray spectroscopies. In a further step, we vertically align the NWs by conformal deposition of a SiO2 shell. Such orientation is critical to analyze the magnetic properties of the FePcCl and FePc supported NWs. A ferromagnetic behavior below 30 K with an easy axis perpendicular to the phthalocyanine plane was observed in the two cases with the FePcCl nanowires presenting a wider hysteresis. These results open the path to the fabrication of nanostructured one-dimensional small-molecule spintronic devices.

This work reports the Calcium-Looping (CaL) multicycle performance under energy storage and CO2 capture conditions of different Al-composites prepared by milling mixtures of nanoalumina and natural limestone powders. The micro-and nanostructure of the composites have been analyzed by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy as affected by the type of CaL conditions employed, either for energy storage in Concentrated Solar Power (CSP) plants or for post-combustion CO2 capture. Two types of calcium aluminates are formed under these diverse CaL conditions. A calcium aluminate with ratio Ca/Al < 1 (Ca4Al6O13) is formed under CaL-CSP conditions, which helps stabilize the CaO microstructure and mitigate pore-plugging. On the other hand, a crystalline phase Ca3Al2O6 is formed (Ca/Al > 1) under CaL-CO2 capture conditions presumably due to the higher calcination temperature, which withdraws from the sorbent a relatively higher amount of active Ca. Moreover, the addition of nano-alumina, and the consequent generation of calcium aluminate, affects in a diverse way the microstructure and morphology of the CaO particles as depending on the CaL application, which critically modifies the performance of the composites.