Browsing by Author "Gracia, F."

Now showing 1 - 6 of 6
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    CO2 methanation over nickel-zro2 catalyst supported on carbon nanotubes: A comparison between two impregnation strategies
    (2018) Romero-Saez, M.; Dongil, A. B.; Benito, N.; Espinoza-Gonzalez, R.; Escalona, N.; Gracia, F.
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    Enhanced hydrogen adsorption properties of mesoporous nano-TiO2@SnO2
    (2023) Rajendran, Saravanan; Gnanasekaran, Lalitha; Hoang, Tuan K. A.; Diaz-Droguett, D. E.; Gracia, F.; Gracia-Pinilla, M. A.
    Today, hydrogen as being one of the most advantageous energy supplies for various applications and specifically not with carbon emissions, alluring strategies are made possible for its production and storage. Since the metal oxides (MOs) semiconductors give rise to the development of new technologies related to renewable energy and environmental issues, this work is envisioned to study the hydrogen adsorption properties of TiO2@SnO2 catalyst synthesized via novel approach by integrating sol-gel and thermal decomposition methods. The synthesized TiO2 and its composite have been analyzed by sophisticated instruments to reveal the drastic enhancement of hydrogen adsorption. In this work, hydrogen measurements were accomplished by quartz crystal (QC) microbalance method. The Raman scattering experiment of the composite revealed the lower peak intensity compared with pure TiO2, which demonstrated the surface defects that created oxygen vacancies with reduced oxidation states of the metal centers. Meanwhile, the mesoporous nanostructure of TiO2@SnO2 could be confirmed via High resolution transmission electron (HR-TEM) microscopic analysis. Besides, the intermediate states of the composite were analyzed through Photoluminescence (PL) spectra which demonstrated the delay in recombining charges. The Barrett-Joyner- Halenda (BJH) method illustrated the larger pore size and pore volume with decreased surface area of the composite. The addition of SnO2 into TiO2 has reported 4 times greater the adsorption of pristine TiO2 particles, because of the capacity of SnO2 to hinder pores. Moreover, the titania oxidation states play a predominant role in the procurement of larger H2 adsorption. Also, the Ti4+ and Sn4+ reveal fragile Kubas type of adsorption that facilitated the hydrogen storage.
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    Hydrogen adsorption properties of Ag decorated TiO2 nanomaterials
    (2018) Rajendran, Saravanan; Hoang, Tuan K.A.; Boukherroub, Rabah; Díaz Droguett, Donovan Enrique; Gracia, F.; Gracia-Pinilla, M.A.; Akbari-Fakhrabadi, A.; Gupta, Vinod Kumar
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    Influence of the monoclinic and tetragonal zirconia phases on the water gas shift reaction. A theoretical study
    (2013) Cerón, M.; Herrera Pisani, Bárbara Andrea; Araya, P.; Gracia, F.; Toro Labbé, Alejandro
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    Photosynthesis of H2 and its storage on the Bandgap Engineered Mesoporous (Ni2+/Ni3+)O @ TiO2 heterostructure
    (2020) Raju, Kumar; Rajendran, Saravanan; Hoang, Tuan K. A.; Durgalakshmi, D.; Qin, Jiaqian; Diaz-Droguett, D. E.; Gracia, F.; Gracia-Pinilla, M. A.
    A noble-metal free and surface defect-induced mesoporous mixed valent NiO decorated TiO2 heterostructure with tuned bandgap has been successfully prepared. Its outstanding visible-light driven hydrogen evolution and its excellent H-2 storage ability have been examined and confirmed. The formation of oxygen vacancies by surface defect creates the Ni3+ and Ti3+ on the interface of the heterostructure induce the efficient H-2 evolution, benchmarked by 1200% enhancement in catalytic performance. The underlying chemistries include the near-unity occupancy of e(g) orbital (t(2g)(6) e(g)(1)) of Ni3+ which speeds up the electron transfer and significantly promote the excellent electron-hole separation efficiency, establishes the outstanding overall charge-transfer efficiency and long-term photocatalytic activity in the visible light spectrum. Multiple Ti3+ adsorption centers in the structure attract multiple intact H-2 molecules per each center via a sigma - pi bonding motif - namely the Kubas interaction - which leads to 480% higher H-2 adsorption capability against the performance of the pristine mesoporous TiO2. Not only the significant results, the study also provide an air-stable synthetic method on the basis of low-cost and abundant materials, which are strongly favoured for scaling up production.
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    The European Solar Telescope
    (2022) Noda, C. Quintero; Schlichenmaier, R.; Bellot Rubio, L. R.; Lofdahl, M. G.; Khomenko, E.; Leenaarts, J.; Kuckein, C.; Gonzalez Manrique, S. J.; Gunar, S.; Nelson, C. J.; Rodriguez, J. de la Cruz; Tziotziou, K.; Tsiropoula, G.; Aulanier, G.; Aboudarham, J.; Allegri, D.; Alsina Ballester, E.; Amans, J. P.; Asensio Ramos, A.; Bailen, F. J.; Balaguer, M.; Baldini, V; Balthasar, H.; Barata, T.; Barczynski, K.; Barreto Cabrera, M.; Baur, A.; Bechet, C.; Beck, C.; Belio-Asin, M.; Bello-Gonzalez, N.; Belluzzi, L.; Bentley, R. D.; Berdyugina, S., V; Berghmans, D.; Berlicki, A.; Berrilli, F.; Berkefeld, T.; Bettonvil, F.; Bianda, M.; Bienes Perez, J.; Bonaque-Gonzalez, S.; Brajsa, R.; Bommier, V; Bourdin, P-A; BurgosMartin, J.; Calchetti, D.; Calcines, A.; Calvo Tovar, J.; Campbell, R. J.; Carballo-Martin, Y.; Carbone, V; Carlin, E. S.; Carlsson, M.; Castro Lopez, J.; Cavaller, L.; Cavallini, F.; Cauzzi, G.; Cecconi, M.; Chulani, H. M.; Cirami, R.; Consolini, G.; Coretti, I; Cosentino, R.; Cozar-Castellano, J.; Dalmasse, K.; Danilovic, S.; Ovelar, M. De Juan; Del Moro, D.; del Pino Aleman, T.; del Toro Iniesta, J. C.; Denker, C.; Dhara, S. K.; Di Marcantonio, P.; Baso, C. J. Diaz; Diercke, A.; Dineva, E.; Diaz-Garcia, J. J.; Doerr, H-P; Doyle, G.; Erdelyi, R.; Ermolli, I; Escobar Rodriguez, A.; Esteban Pozuelo, S.; Faurobert, M.; Felipe, T.; Feller, A.; Feijoo Amoedo, N.; Femenia Castella, B.; Fernandes, J.; Ferro Rodriguez, I; Figueroa, I; Fletcher, L.; Franco Ordovas, A.; Gafeira, R.; Gardenghi, R.; Gelly, B.; Giorgi, F.; Gisler, D.; Giovannelli, L.; Gonzalez, F.; Gonzalez, J. B.; Gonzalez-Cava, J. M.; Gonzalez Garcia, M.; Gomory, P.; Gracia, F.; Grauf, B.; Greco, V; Grivel, C.; Guerreiro, N.; Guglielmino, S. L.; Hammerschlag, R.; Hanslmeier, A.; Hansteen, V; Heinzel, P.; Hernandez-Delgado, A.; Hernandez Suarez, E.; Hidalgo, S. L.; Hill, F.; Hizberger, J.; Hofmeister, S.; Jagers, A.; Janett, G.; Jarolim, R.; Jess, D.; Jimenez Mejias, D.; Jolissaint, L.; Kamlah, R.; Kapitan, J.; Kasparova, J.; Keller, C. U.; Kentischer, T.; Kiselman, D.; Kleint, L.; Klvana, M.; Kontogiannis, I; Krishnappa, N.; Labrosse, N.; Lagg, A.; Degl'Innocenti, E. Landi; Langlois, M.; Lafon, M.; Laforgue, D.; Le Men, C.; Lepori, B.; Lepreti, F.; Lindberg, B.; Lilje, P. B.; Ariste, A. Lopez; Lopez Fernandez, V. A.; Lopez Jimenez, A. C.; Lopez Lopez, R.; Sainz, R. Manso; Marassi, A.; Marco de la Rosa, J.; Marino, J.; Marrero, J.; Martin, A.; Martin Galvez, A.; Martin Hernando, Y.; Masciadri, E.; MartinezGonzalez, M.; Matta-Gomez, A.; Mato, A.; Mathioudakis, M.; Matthews, S.; Mein, P.; Merlos Garcia, F.; Moity, J.; Montilla, I; Molinaro, M.; Molodij, G.; Montoya, L. M.; Munari, M.; Murabito, M.; Nunez Cagigal, M.; Oliviero, M.; Orozco Suarez, D.; Ortiz, A.; Padilla-Hernandez, C.; Paez Mana, E.; Paletou, F.; Pancorbo, J.; Pastor Canedo, A.; Yabar, A. Pastor; Peat, A. W.; Pedichini, F.; Peixinho, N.; Penate, J.; Perez de Taoro, A.; Peter, H.; Petrovay, K.; Piazzesi, R.; Pietropaolo, E.; Pleier, O.; Poedts, S.; Potzi, W.; Podladchikova, T.; Prieto, G.; Quintero Nehrkorn, J.; Ramelli, R.; Ramos Sapena, Y.; Rasilla, J. L.; Reardon, K.; Rebolo, R.; Regalado Olivares, S.; Reyes Garcia-Talavera, M.; Riethmuller, T. L.; Rimmele, T.; Rodriguez Delgado, H.; Rodriguez Gonzalez, N.; Rodriguez-Losada, J. A.; Rodriguez Ramos, L. F.; Romano, P.; Roth, M.; vander Voort, L. Rouppe; Rudawy, P.; Ruiz de Galarreta, C.; Rybak, J.; Salvade, A.; Sanchez-Capuchino, J.; Sanchez Rodriguez, M. L.; Sangiorgi, M.; Sayede, F.; Scharmer, G.; Scheiffelen, T.; Schmidt, W.; Schmieder, B.; Scire, C.; Scuderi, S.; Siegel, B.; Sigwarth, M.; Simoes, P. J. A.; Snik, F.; Sliepen, G.; Sobotka, M.; Socas-Navarro, H.; Sola La Serna, P.; Solanki, S. K.; Soler Trujillo, M.; Soltau, D.; Sordini, A.; Sosa Mendez, A.; Stangalini, M.; Steiner, O.; Stenflo, J. O.; Stepan, J.; Strassmeier, K. G.; Sudar, D.; Suematsu, Y.; Sutterlin, P.; Tallon, M.; Temmer, M.; Tenegi, F.; Tritschler, A.; Trujillo Bueno, J.; Turchi, A.; Utz, D.; van Harten, G.; VanNoort, M.; van Werkhoven, T.; Vansintjan, R.; Vaz Cedillo, J. J.; Vega Reyes, N.; Verma, M.; Veronig, A. M.; Viavattene, G.; Vitas, N.; Vogler, A.; von der Luhe, O.; Volkmer, R.; Waldmann, T. A.; Walton, D.; Wisniewska, A.; Zeman, J.; Zeuner, F.; Zhang, L. Q.; Zuccarello, F.; Collados, M.
    The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Telescope Heliographique pour l'etude du Magnetisme et des Instabilites Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems.