65 research outputs found

    White-emitting organometallo-silica nanoparticles for sun-like light-emitting diodes

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    This work discloses a radically new way to prepare white-emitting hybrid nanoparticles, whose implementation in lighting devices provides encouraging proof-of-concept performances towards alternative sunlight sources. In detail, the new synthetic approach is based on the kinetic control of the formation of organometallic dots, built via the condensation of three emitting iridium(III) complexes, which are subsequently transformed into mesoporous silica nanoparticles. Our novel hybrid systems, which are exceptionally stable under harsh irradiation and thermal stress environments, show a bright white emission with a record photoluminescence quantum yield. Their remarkable performance prompted us to implement them into single-component hybrid light-emitting diodes (HLEDs), achieving a high-quality sunlight source that is stable for >2000 hours with linearly extrapolated stabilities of >10 000 h. This represents one of the most stable HLEDs reported so far, while the versatility of our synthesis approach with respect to the type of emitters opens new opportunities for the design and fabrication of white-emitting color down-converters for HLEDs in the future.C. E., E. L. and J. R. B acknowledge Spanish MINECO and AEI/FEDER (ref. CTQ2016-78463-P). C. E. also thanks Universidad de La Rioja for a grant. E. F. and R.D.C. acknowledge the program “Ayudas para la atracción de talento investigador – Modalidad 1 of the Consejería de Educación, Juventud y Deporte – Comunidad de Madrid with the reference number 2016-T1/IND-1463”. R. D. C. acknowledges Spanish MINECO for the Ramón y Cajal program (RYC-2016-20891). J.G.M. acknowledges Spanish MINECO and AEI/FEDER (ref. CTQ2014-60017-R). E.S. thanks Spanish MINECO and AEI/FEDER (ref. CTQ2015-74494-JIN) and the University of Alicante (“Ayudas para la captación de talento” program with the reference number UATALENTO16-03)

    Hybrid organometallo-silica catalysts for sustainable visible-light promoted olefin isomerization

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    The use of visible light as a clean and affordable reagent has turned photocatalysis into a green and powerful tool in synthetic chemistry. However, most of these photocatalytic processes are carried out under homogeneous conditions, which requires expensive catalysts that are difficult to recover and recycle. One way to overcome this problem is to incorporate the visible-active species into porous solid matrices. However, integrating these active species into the matrix to achieve a stable and active heterogeneous photocatalyst is not easy, and has usually been done by post-synthetic strategies. Herein, we describe the use of the highly emissive cyclometalated complex [Ir(dfppy)2(dasipy)]PF6 as a building block for the in-situ synthesis of four different silica-based heterogeneous photocatalysts, and a related post-synthetic grafted material. These highly stable materials have been assessed in the energy transfer photo-isomerization reaction of trans- to cis-stilbene under blue light and mild conditions; showing not only high isomerization yields (ca. 80 %), but also easy recovery and excellent recyclability (up to 100 % after 7 cycles).This work was supported by the Spanish MCIN/AIE/10.13039/501100011033, the ‘‘ERDF A way of making Europe’’, the ‘‘European Union’’ (projects PID2019-109742GB-I00 and PID2021-128761OB-C21), Gobierno de la Rioja (Project FORTALECE 2021/01) and Generalitat Valenciana (Regional Project AICO/2021/037 - Conselleria d’Innovació, Universitats, Ciència i Societat Digital)

    Meeting High Stability and Efficiency in Hybrid Light‐Emitting Diodes Based on SiO2/ZrO2 Coated CsPbBr3 Perovskite Nanocrystals

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    Significant advances are realized in perovskite‐converted hybrid light‐emitting diodes (pc‐HLEDs). However, long‐living devices at high efficiencies still represent a major milestone with average stabilities of <200 h at ≈50 lm W−1 under low applied currents (<15 mA). Herein, a dual metal oxide‐coated CsPbBr3@SiO2/ZrO2 composite is prepared in a one‐pot synthesis through the kinetic control of the sol–gel reaction, followed by a gentle drying process in air. These hybrid nanoparticles show photoluminescence quantum yields of ≈65% that are stable under temperature, ambient, and irradiation stress scenarios. This is translated to pc‐HLEDs with a near‐unity conversion efficiency at any applied current, high efficiencies around 75 lm W−1, and one of the most remarkable stabilities of ≈200 and 700 h at 100 and 10 mA, respectively. In addition, the device degradation mechanism is thoughtfully rationalized comparing devices operating under ambient/inert conditions. As such, this work provides three milestones: i) a new room temperature one‐pot protocol to realize the first SiO2/ZrO2 metal oxide coating that effectively protects the emitting perovskite nanoparticle core, ii) one of the most stable and efficient pc‐HLEDs operating under ambient condition at any applied current, and iii) new insights for the degradation of pc‐HLEDs.R.D.C. acknowledges the program “Ayudas para la atracción de talento investigador—Modalidad 1 of the Consejería de Educación, Juventud y Deporte—Comunidad de Madrid with the Reference No. 2016‐T1/IND‐ 1463,” Spanish Ministry of Economy and Competitiveness (MINECO) for the Ramón y Cajal program (RYC‐2016‐20891), and HYNANOSC (RTI2018‐099504‐A‐C22). Y.Y.D. also thanks the financial support from China Scholarship Council (No. 201808440326). This work was supported by the Spanish MICINN and Agencia Estatal de Investigación (AEI)/European Regional Development Fund (FEDER) (Projects CTQ2015‐74494‐JIN, CTQ2016‐78463‐P, RTI2018‐099504‐B‐C21/A‐C22, and PID2019‐109742GB‐I00). E.S. thanks Universidad de Alicante through the “Programa de Retención de Talento” (ref. UATALENTO16‐03) and C.E. thanks Universidad de La Rioja for a grant. Open access funding enabled and organized by Projekt DEAL

    Highly emissive hybrid mesoporous organometallo-silica nanoparticles for bioimaging

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    Production of mesoporous silica nanoparticles (MSNs) with uniform textural characteristics and imaging properties on a large scale is still a challenge. Thus, the design of simple and scalable methods to obtain reproducible functionalized MSNs has become even more relevant. Herein, we describe an in situ strategy for the synthesis and surface functionalization of highly luminescent mesoporous organometallo-silica nanoparticles. Using the [Ir(dfppy)2(dasipy)]PF6 chromophore and TEOS as sol–gel precursors and different capping agents, such as DMDES or APTES, three different emissive MSNs were prepared (NPOH_IS, NPMe_IS and NPNH2_IS), each containing hydroxyl, methyl and amine groups on their surfaces, respectively. All three were tested on human tumor A549 (lung carcinoma) and HeLa (cervix carcinoma) cell lines, showing intense and stable yellow phosphorescence, biocompatibility and efficient internalization. Moreover, NPMe_IS nanoparticles showed excellent colloidal stability, both in water and biological media, and a BET area of 1120 m2 g−1, making them not only luminescent biomarkers, but potentially also controlled delivery vectors.This work was supported by the Spanish MCIN/AIE/10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union” (projects CTQ2015-74494-JIN, RTI2018-099504-B-C21 and PID2019-109742GB-I00) and the Agencia de Desarrollo Económico de La Rioja (Gobierno de la Rioja. Project 2017-I-IDD-00031). E.S. also thanks the University of Alicante through the “Programa de Retención de Talento” (ref. UATALENTO16-03). E.A.-A. is grateful to the Spanish Association Against Cancer (AECC) for her Ph.D. fellowship

    Bottom-up construction of highly photoactive dye-sensitized titania using Ru(II) and Ir(III) complexes as building blocks

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    The one-pot co-condensation of tetrabutyl orthotitanate (TBOT) and the neutral Ru(II) N3 dye or the new cationic Ir(III) complex [Ir(ppy)2(3,3′-H2dcbpy)]PF6 have yielded novel hybrid in-situ titanias, which present an exceptional stability against leaching or photodegradation of the coordination dye. The main advantages of this strategy are: i) high dye incorporation level, ii) narrowing band gap and iii) high stability. These materials exhibit much higher photocatalytic activity, under both UV and visible light, not only than the dye-free titania but also than the related dye-sensitized titania prepared by post-synthetic grafting. This in-situ synthetic approach is a promising alternative route to prepare highly stable dye-sensitized materials with great applicability potential.We thank the Spanish MINECO (Projects CTQ2013-45518-P and CTQ2014-60017-R) for financial support

    Impact of Early Interferon-β Treatment on the Prognosis of Patients with COVID-19 in the First Wave: A Post Hoc Analysis from a Multicenter Cohort

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    Background: Interferon-p is an attractive drug for repurposing and use in the treatment of COVID-19, based on its in vitro antiviral activity and the encouraging results from clinical trials. The aim of this study was to analyze the impact of early interferon-p treatment in patients admitted with COVID-19 during the first wave of the pandemic. Methods: This post hoc analysis of a COVID-19@Spain multicenter cohort included 3808 consecutive adult patients hospitalized with COVID-19 from 1 January to 17 March 2020. The primary endpoint was 30-day all-cause mortality, and the main exposure of interest was subcutaneous administration of interferon-beta, defined as early if started <= 3 days from admission. Multivariate logistic and Cox regression analyses were conducted to identify the associations of different variables with receiving early interferon-beta therapy and to assess its impact on 30-day mortality. A propensity score was calculated and used to both control for confounders and perform a matched cohort analysis. Results: Overall, 683 patients (17.9%) received early interferon-p therapy. These patients were more severely ill. Adjusted HR for mortality with early interferon-p was 1.03 (95% CI, 0.82-1.30) in the overall cohort, 0.96 (0.82-1.13) in the PS-matched subcohort, and 0.89 (0.60-1.32) when interferon-beta treatment was analyzed as a time-dependent variable. Conclusions: In this multicenter cohort of admitted COVID-19 patients, receiving early interferon-beta therapy after hospital admission did not show an association with lower mortality. Whether interferon-beta might be useful in the earlier stages of the disease or specific subgroups of patients requires further research

    Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

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    Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population
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