Resultados de investigación

Citation corpus composed by 85 articles taken randomly from ACL Anthology with a total of 2195 bibliography cites.

This study explores the surface modification of TiO2 P25 with nanosized copper (Cu) or nickel (Ni) for photocatalytic hydrogen production via water splitting. Photocatalysts with 1 or 5 wt % metal loadings were synthesized using a cost-effective impregnation method and were tested as-prepared (XM/P25) and after thermal reduction under hydrogen flow (XM/P25-r). Pre-calcination was omitted to simplify the synthesis. The characterization of the photocataysts revealed key physicochemical, optical, and electronic properties, including the surface distribution and oxidation states of metal species and their interaction with TiO2. TEM and EDS showed well-distributed metal species forming nanometric domains on the P25 surface. XPS and Auger spectroscopy allowed the identification of different metal oxidation states and species. After reduction, Cu0 and Ni0 phases coexisted with oxidized species, enhancing light absorption and reducing the electron–hole recombination, confirmed by UV–vis DRS and PL, respectively. Cu species seemed to exhibit stronger interaction with TiO2 than Ni ones. Photochemical results showed that only the thermally reduced photocatalysts led to immediate hydrogen production, highlighting the need for zero-valent metal species for an efficient hydrogen generation. 5Ni/P25-r and 5Cu/P25-r outperformed P25, achieving 331 and 284 μmol H2·gcat–1·h–1, respectively, compared to 261 μmol H2·gcat–1·h–1 for P25. Although in terms of hydrogen production 5Ni/P25-r slightly outperformed 5Cu/P25-r, the latter demonstrated greater stability, possibly due to the oxidation of Ni during the tests. As-prepared photocatalysts can be activated after extended UV irradiation; for instance, 5Cu/P25 starts producing hydrogen after 10 h of irradiation as a result of the in situ metal reduction, confirmed by the color change in the photocatalyst.

This file contains data of the figures of the experiments performed and of the microscopy images.

Datos de investigación que han permitido escribir el artículo identificado con el doi https://doi.org/10.1007/s13399-023-04045-8

En el fichero se incluyen los datos del trabajo experimental que han permitido escribir el artículo, el resumen de cuyo contenido se indica a continuación: The study pursues the optimization of active sites in TiO2-based photocatalysts modified with copper for hydrogen production via cellulose photo-reforming. Copper was incorporated, by impregnation, in the commercial titania P25 and in hydrothermally synthesized TiO2 which has a larger surface area and contains only anatase. The hydrothermal synthesis method was also employed for the one-pot preparation of TiO2–Cu photocatalysts. The effect of the copper loading was investigated in the three series of samples. Characterization techniques, including XPS, XRD, UV–vis, and PL spectroscopy, confirmed structural and electronic modifications induced by Cu incorporation, which would directly influence the photocatalytic efficiency. The activity tests demonstrated a significant enhancement in H₂ evolution upon Cu loading, being the photocatalysts prepared by the one-pot method the most active ones for hydrogen generation, with the highest H2/CO2 ratio and leading to the highest concentration of sugars and organic acids in solution, compared with the catalysts prepared by impregnation. The superior performance of these photocatalysts has been attributed to their increased surface area that allows a higher Cu loading with optimised distribution of active sites. In particular, the catalysts with 3 wt% Cu is the one exhibiting the highest efficiency, producing 2752 µmol·h⁻¹·gcat⁻¹, and being recyclable.

Dataset of literary reports published at the end of December in the "Babelia" supplement, of the newspaper El País, between 2010 and 2020, specifically those that contain keywords related to the best books of the year and are available openly to users of internet The number of works listed varies according to the year, but an obvious variation is seen towards the middle of the period (when from around 25 books, in the first years, they go to 10, from 2013 to 2016). From this moment on, an increasing trend can be seen, first to 20 books (again) and then, from 2018, to 50 books. In total, the database yields 283 items that include information on author, title, genre, publisher, year, language of publication and language of origin.

Here we include a dataset of 86 pictures of concrete textures. The numerical name codifies the texture according to he following parameters:(First digit: Slump) Primer dígito: Consistencias: (First digit: Slump) - "s": Seco -- 1 (range [0-25] mm) - "p": Plástico -- 2 (range [25-50] mm) - "b": Blanda -- 3 (range [50-90] mm) - "f": Fluida -- 4 (range [90-150] mm) Segundo dígito: Método de fabricación: (Second digit: Compaction method) - "p": Pica -- 1 (ramming with a steel bar) - "m": Maza -- 2 (tapping with a rubber mallet) - "v": Vibrador -- 3 (electric vibrator) Tercer dígito: Material del encofrado: (Third digit: Formwork material) - "m": Madera -- 1 (wood) - "a": Acero -- 2 (steel)

UR is a data sheet to build a database. It is a data sheet to be clear, concise and easily available, and it provides as much information as possible. Thus, the UR (Unit of Reconstruction/Recreation) data sheet is comprehensive and simple, and has a limited number of entries containing the main and essential information of the elements of each virtualization project. In order to standardize the processes and the definitions a limited and predetermined number and range of unfolding alternatives are provided in the database.

To produce hydrogen and revalorize lignocellulosic residues, Cu/TiO2 and Ni/TiO2 photocatalysts (metal loading 1 or 5 wt%), as-prepared and after thermal reduction treatment, were tested for the photoreforming of cellulose and almond shell derived-substrates. Net photoreforming contributions were quantified by subtracting the individual contributions of photodegradation and photocatalyzed water splitting. Only milled cellulose (MC) and the liquid from the hydrothermal carbonization of milled almond shell (HMAS-L2) substrates proved effective for photoreforming, yielding significantly higher hydrogen productions than those obtained from substrates photodegradation and water splitting. As-prepared Cu/TiO2 showed efficient photocatalytic activity due to the facile in-situ reduction of Cu species. Conversely, Ni/TiO2 photocatalysts became active only after the reduction treatment, when partial formation of Ni0 species enhanced charge separation. The presence of reduced metals significantly improved photoactivity by decreasing charge recombination. The highest hydrogen productions reached were 2320 μmol·gcat−1· h−1 and 2440 μmol·gcat−1·h−1 with MC_5Ni-P25-r and HMAS-L2_5Cu/P25-r, respectively, surpassing previously reported literature values. The H2/CO2 molar ratios, with values close to the theoretical stoichiometric ratio (≈2), confirmed the predominant photoreforming pathway, while deviations indicated concurrent photodegradation and/or photoinduced water splitting. Tests with scavengers confirmed the effective photoreforming with MC and HMAS-L2 substrates, in contrast to milled almond shell and its derived solids.