Staff directory
Marcos Rosado Iglesias
Specialist Technician
marcos.rosado(ELIMINAR)@icn2.cat
Electron Microscopy Unit
- ORCID: 0000-0003-3938-9132
Publications
2022
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Structural peculiarities of e-Fe2O3/GaN epitaxial layers unveiled by high-resolution transmission electron microscopy and neutron reflectometry
Suturin, SM; Dvortsova, PA; Snigirev, LA; Ukleev, VA; Hanashima, T; Rosado, M; Ballesteros, B Materials Today Communications; 33 2022. 10.1016/j.mtcomm.2022.104412. IF: 3.662
2021
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Cover Feature: Facing Seawater Splitting Challenges by Regeneration with Ni ? Mo ? Fe Bifunctional Electrocatalyst for Hydrogen and Oxygen Evolution (ChemSusChem 14/2021)
Ros, Carles; Murcia?López, Sebastian; Garcia, Xenia; Rosado, Marcos; Arbiol, Jordi; Llorca, Jordi; Morante, Joan R. Chemsuschem; 14 (14): 2782 - 2782. 2021. 10.1002/cssc.202101257. IF: 8.928
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Facing Seawater Splitting Challenges by Regeneration with Ni−Mo−Fe Bifunctional Electrocatalyst for Hydrogen and Oxygen Evolution
Ros C., Murcia-López S., Garcia X., Rosado M., Arbiol J., Llorca J., Morante J.R. ChemSusChem; 14 (14): 2872 - 2881. 2021. 10.1002/cssc.202100194. IF: 8.928
Hydrogen, produced by water splitting, has been proposed as one of the main green energy vectors of the future if produced from renewable energy sources. However, to substitute fossil fuels, large amounts of pure water are necessary, scarce in many world regions. In this work, we fabricate efficient and earth-abundant electrodes, study the challenges of using real seawater, and propose an electrode regeneration method to face undesired salt deposition. Ni−Mo−Fe trimetallic electrocatalyst is deposited on non-expensive graphitic carbon felts both for hydrogen (HER) and oxygen evolution reactions (OER) in seawater and alkaline seawater. Cl− pitting and the chlorine oxidation reaction are suppressed on these substrates and alkalinized electrolyte. Precipitations on the electrodes, mainly CaCO3, originating from seawater-dissolved components have been studied, and a simple regeneration technique is proposed to rapidly dissolve undesired deposited CaCO3 in acidified seawater. Under alkaline conditions, Ni−Mo−Fe-based catalyst is found to reconfigure, under cathodic bias, into Ni−Mo−Fe alloy with a cubic crystalline structure and Ni : Fe(OH)2 redeposits whereas, under anodic bias, it is transformed into a follicular Ni:FeOOH structure. High productivities over 300 mA cm−2 and voltages down to 1.59 V@10 mA cm−2 for the overall water splitting reaction have been shown, and electrodes are found stable for over 24 h without decay in alkaline seawater conditions and with energy efficiency higher than 61.5 % which makes seawater splitting promising and economically feasible. © 2021 Wiley-VCH GmbH
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Heat-up colloidal synthesis of shape-controlled cu-se-s nanostructures—role of precursor and surfactant reactivity and performance in n2 electroreduction
Mourdikoudis S., Antonaropoulos G., Antonatos N., Rosado M., Storozhuk L., Takahashi M., Maenosono S., Luxa J., Sofer Z., Ballesteros B., Thanh N.T.K., Lappas A. Nanomaterials; 11 (12, 3369) 2021. 10.3390/nano11123369. IF: 5.076
Copper selenide-sulfide nanostructures were synthesized using metal-organic chemical routes in the presence of Cu-and Se-precursors as well as S-containing compounds. Our goal was first to examine if the initial Cu/Se 1:1 molar proportion in the starting reagents would always lead to equiatomic composition in the final product, depending on other synthesis parameters which affect the reagents reactivity. Such reaction conditions were the types of precursors, surfactants and other reagents, as well as the synthesis temperature. The use of ‘hot-injection’ processes was avoided, focusing on ‘non-injection’ ones; that is, only heat-up protocols were employed, which have the advantage of simple operation and scalability. All reagents were mixed at room temperature followed by further heating to a selected high temperature. It was found that for samples with particles of bigger size and anisotropic shape the CuSe composition was favored, whereas particles with smaller size and spherical shape possessed a Cu2−xSe phase, especially when no sulfur was present. Apart from elemental Se, Al2Se3 was used as an efficient selenium source for the first time for the acquisition of copper selenide nanostructures. The use of dodecanethiol in the presence of trioctylphosphine and elemental Se promoted the incorporation of sulfur in the materials crystal lattice, leading to Cu-Se-S compositions. A variety of techniques were used to characterize the formed nanomaterials such as XRD, TEM, HRTEM, STEM-EDX, AFM and UV-Vis-NIR. Promising results, especially for thin anisotropic nanoplates for use as electrocatalysts in nitrogen reduction reaction (NRR), were obtained. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
2018
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Encapsulation of cationic iridium(iii) tetrazole complexes into a silica matrix: Synthesis, characterization and optical properties
Zanoni I., Fiorini V., Rosado M., Ballesteros B., Androulidaki M., Blosi M., Ortelli S., Stagni S., Dondi M., Costa A.L. New Journal of Chemistry; 42 (12): 9635 - 9644. 2018. 10.1039/c8nj01514g. IF: 3.201
Herein we report the easy incorporation of brightly phosphorescent cationic iridium(iii) tetrazole complexes into a silica based matrix via an easily scalable colloidal process. For this purpose, two cationic Ir(iii) emitters bearing 5-aryl tetrazole ligands (R-CN4) were selected: blue [F2IrPTZ-Me]+ (C^N = F2ppy; N^N = PTZ-Me-2-(2-methyl-2H-tetrazol-5-yl)pyridine) and red [IrQTZ-Me]+ (C^N = ppy; N^N = QTZ-Me-2-(2-methyl-2H-tetrazol-5-yl)quinoline). The cationic complexes were readily adsorbed to negatively charged silica nanoparticles and trapped in the sol-gel matrix. The sol-to-solid phase transfer was performed by using an innovative spray-freeze-drying technique, leading to the formation of phosphorescent solid micro-granules. The structural and optical characterisation of the Ir(iii) complexes together with SiO2 nanoparticles, nanosols (Ir@SiO2) and powders (Ir@SiO2 powders), revealed how the presence of the Ir(iii)-based complexes did not alter the morphology of the colloidal silica or granulated phases. Moreover, the silica matrix did not interfere with the optical properties of the embedded complexes. The distribution of [F2IrPTZ-Me]+ and [IrQTZ-Me]+ in the spray-freeze-dried powders was qualitatively evaluated by fluorescence microscopy, revealing how the luminescent particles were homogeneously dispersed all over the silica matrix. Interestingly, in aqueous solution the release of complex [F2IrPTZ-Me]+ from the corresponding Ir@SiO2 powder is almost negligible, therefore suggesting that a strong interaction occurs between the host-silica matrix and the Ir(iii) guest complex. © 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.