10 research outputs found

    Ultrathin Transparent B-C-N Layers Grown on Titanium Substrates with Excellent Electrocatalytic Activity for the Oxygen Evolution Reaction

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Energy Materials, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acsaem.9b02339Ultrathin B-C-N layers grown on Ti substrates are investigated as efficient anodes for electrochemical water splitting. A fast and direct synthetic route has been used based on plasma-enhanced chemical vapor deposition with methylamine borane as a single-source molecular precursor. The effect of growth time on the morphological and structural properties and on the chemical composition of the layers has been investigated by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy coupled with electron energy loss spectroscopy. Flat B-C-N layers on top of an amorphous titanium oxide layer present at the Ti surface have been obtained by using short growth times, while longer growth times give rise to core/shell structures formed by vertical wall B-C-N layers and titanium carbonitride phases. The obtained layers present enhanced electrocatalytic activity for the oxygen evolution reaction in alkaline aqueous solutions. Moreover, because of their ultrathin nature, the B-C-N layers preserve the photocurrents of the underlying titanium oxide layer, acting as transparent electrodes with high conductivity for the photogenerated charge carriers and improved electrocatalytic activity for the oxidation of water to oxygen gasThis work has been funded under RTI2018-099794-B-I00 grant of Spanish MICINN and by PRIN Grant FERMAT (2017KFY7XF) of Italian MIU

    A fast synthesis route of boron-carbon-nitrogen ultrathin layers towards highly mixed ternary B-C-N phases

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    We report a direct and fast synthesis route to grow boron-carbon-nitrogen layers based on microwave-assisted plasma enhanced chemical vapour deposition (PECVD) by using methylamine borane as a single source molecular precursor. This easy and inexpensive method allows controlled and reproducible growth of B-C-N layers onto thin Cu foils. Their morphological, structural, chemical, optical and transport properties have been thoroughly characterized by a number of different microscopies, transport and spectroscopic techniques. Though disorder and segregation into C-rich and h-BN-rich domains have been observed in ultrathin flat few layers, high doping levels have been reached, inducing strong modifications of the electronic, optical and transport properties of C-rich and h-BN-rich phases. This synthesis procedure can open new routes towards the achievement of homogeneous highly mixed ternary B-C-N phase

    MoS2 photoelectrodes for hydrogen production: Tuning the S-vacancy content in highly homogeneous ultrathin nanocrystals

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    Tuning the electrocatalytic properties of MoS2 layers can be achieved through different paths, such as reducing their thickness, creating edges in the MoS2 flakes, and introducing S-vacancies. We combine these three approaches by growing MoS2 electrodes by using a special salt-assisted chemical vapor deposition (CVD) method. This procedure allows the growth of ultrathin MoS2 nanocrystals (1-3 layers thick and a few nanometers wide), as evidenced by atomic force microscopy and scanning tunneling microscopy. This morphology of the MoS2 layers at the nanoscale induces some specific features in the Raman and photoluminescence spectra compared to exfoliated or microcrystalline MoS2 layers. Moreover, the S-vacancy content in the layers can be tuned during CVD growth by using Ar/H2 mixtures as a carrier gas. Detailed optical microtransmittance and microreflectance spectroscopies, micro-Raman, and X-ray photoelectron spectroscopy measurements with sub-millimeter spatial resolution show that the obtained samples present an excellent homogeneity over areas in the cm2 range. The electrochemical and photoelectrochemical properties of these MoS2 layers were investigated using electrodes with relatively large areas (0.8 cm2). The prepared MoS2 cathodes show outstanding Faradaic efficiencies as well as long-term stability in acidic solutions. In addition, we demonstrate that there is an optimal number of S-vacancies to improve the electrochemical and photoelectrochemical performances of MoS2PID2021-126098OB-I00, PID2020-116619GA-C22, TED2021-131788A-I00, SI3/PJI/2021-0050

    Relevance of gastrointestinal manifestations in a large Spanish cohort of patients with systemic lupus erythematosus: what do we know?

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    SLE can affect any part of the gastrointestinal (GI) tract. GI symptoms are reported to occur in >50% of SLE patients. To describe the GI manifestations of SLE in the RELESSER (Registry of SLE Patients of the Spanish Society of Rheumatology) cohort and to determine whether these are associated with a more severe disease, damage accrual and a worse prognosis. METHODS: We conducted a nationwide, retrospective, multicentre, cross-sectional cohort study of 3658 SLE patients who fulfil =4 ACR-97 criteria. Data on demographics, disease characteristics, activity (SLEDAI-2K or BILAG), damage (SLICC/ACR/DI) and therapies were collected. Demographic and clinical characteristics were compared between lupus patients with and without GI damage to establish whether GI damage is associated with a more severe disease. RESULTS: From 3654 lupus patients, 3.7% developed GI damage. Patients in this group (group 1) were older, they had longer disease duration, and were more likely to have vasculitis, renal disease and serositis than patients without GI damage (group 2). Hospitalizations and mortality were significantly higher in group 1. Patients in group 1 had higher modified SDI (SLICC Damage Index). The presence of oral ulcers reduced the risk of developing damage in 33% of patients. CONCLUSION: Having GI damage is associated with a worse prognosis. Patients on a high dose of glucocorticoids are at higher risk of developing GI damage which reinforces the strategy of minimizing glucocorticoids. Oral ulcers appear to decrease the risk of GI damage. © The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology

    Borocarbonitride layers on titanium dioxide nanoribbons for efficient photoelectrocatalytic water splitting

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    Heterostructures formed by ultrathin borocarbonitride (BCN) layers grown on TiO(2) nanoribbons were investigated as photoanodes for photoelectrochemical water splitting. TiO(2) nanoribbons were obtained by thermal oxidation of TiS(3) samples. Then, BCN layers were successfully grown by plasma enhanced chemical vapour deposition. The structure and the chemical composition of the starting TiS(3), the TiO(2) nanoribbons and the TiO(2)-BCN heterostructures were investigated by Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Diffuse reflectance measurements showed a change in the gap from 0.94 eV (TiS(3)) to 3.3 eV (TiO(2)) after the thermal annealing of the starting material. Morphological characterizations, such as scanning electron microscopy and optical microscopy, show that the morphology of the samples was not affected by the change in the structure and composition. The obtained TiO(2)-BCN heterostructures were measured in a photoelectrochemical cell, showing an enhanced density of current under dark conditions and higher photocurrents when compared with TiO(2). Finally, using electrochemical impedance spectroscopy, the flat band potential was determined to be equal in both TiO(2) and TiO(2)-BCN samples, whereas the product of the dielectric constant and the density of donors was higher for TiO(2)-BCN

    A fast synthesis route of boron–carbon–nitrogen ultrathin layers towards highly mixed ternary B–C–N phases

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    We report a direct and fast synthesis route to grow boron–carbon–nitrogen layers based on microwave-assisted plasma enhanced chemical vapour deposition (PECVD) by using methylamine borane as a single source molecular precursor. This easy and inexpensive method allows controlled and reproducible growth of B–C–N layers onto thin Cu foils. Their morphological, structural, chemical, optical and transport properties have been thoroughly characterized by a number of different microscopies, transport and spectroscopic techniques. Though disorder and segregation into C-rich and h-BN-rich domains have been observed in ultrathin flat few layers, high doping levels have been reached, inducing strong modifications of the electronic, optical and transport properties of C-rich and h-BN-rich phases. This synthesis procedure can open new routes towards the achievement of homogeneous highly mixed ternary B–C–N phases

    XV Congreso de Investigación de Estudiantes de Grado en Ciencias de la Salud. XIX Congreso de Ciencias Veterinarias y Biomédicas: trabajos premiados.

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    Trabajos premiados de investigación (clínica, básica) o revisión bibliográfica, en temas relacionados con las Ciencias de la Salud, realizados por alumnos de Grado principalmente de las titulaciones de Biología, Ciencia y Tecnología de los Alimentos, Enfermería, Farmacia, Fisioterapia, Logopedia, Medicina, Nutrición Humana y Dietética, Odontología, Óptica y Optometría, Podología, Psicología, Terapia Ocupacional y Veterinaria.DecanatoFac. de OdontologíaFac. de Ciencias BiológicasFac. de Enfermería, Fisioterapia y PodologíaFac. de FarmaciaFac. de MedicinaFac. de Óptica y OptometríaFac. de PsicologíaFac. de VeterinariaTRUEpu

    Mejor biblioteca, mejores lectores

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    El objetivo principal de este proyecto es poner en marcha una biblioteca escolar en el centro y como consecuencia directa, contribuir a la formación de nuevos y mejores lectores. Se necesita acondicionar un espacio acogedor y agradable, seleccionar un mobiliario práctico y conservarlo en buenas condiciones. En cuanto a los fondos, se debe facilitar el acceso y la rápida localización de los mismos, crear una sección de libros escritos por alumnos, aumentar la sección de libros en inglés, además de regular la adquisición y mantenimiento de los libros. Otro de los objetivos está relacionado con la gestión de la biblioteca como poner en funcionamiento el servicio de préstamo, elaborar un horario, un calendario, crear unas normas de uso y disfrute y preparar exposiciones, jornadas culturales, celebrar el día del Libro, editar un periódico, elaborar guías de lectura y actividades de animación a la lectura. Por tanto, las actividades se dividen en tres tipos: la relacionada con la transformación de la biblioteca, la relacionada con las actividades pedagógicas y la relacionada con la formación del profesorado. La metodología consiste en trabajar en equipo, a veces de forma voluntaria y otras programadas por los profesores. La evaluación del proyecto valora las actividades realizadas a lo largo del curso de forma continua, a través del diálogo con la coordinadora. Ésta se dedica a evaluar cada sesión o actividad mediante la observación directa y la redacción de informes con los resultados obtenidos. Adjunta anexos con números del periódico, folletos, fotografías y ejercicios..Madrid (Comunidad Autónoma). Consejería de Educación. Dirección General de Mejora de la Calidad de la EnseñanzaMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES
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