Hydrogel composites based on chitosan and CuAuTiO2 photocatalysts for hydrogen production under simulated sunlight irradiation

[EN] This study explored the photocatalytic hydrogen evolution reaction (HER) using novel biohydrogel composites comprising chitosan, and a photocatalyst consisting in TiO2 P25 decorated with Au and/or Cu mono- and bimetallic nanoparticles (NPs) to boost its optical and catalytic properties. Low loads of Cu and Au (1 mol%) were incorporated onto TiO2 via a green photodeposition methodology. Characterization techniques confirmed the incorporation of decoration metals as well as improvements in the light absorption properties in the visible light interval (lambda > 390 nm) and electron transfer capability of the semiconductors. Thereafter, Au and/or Cu NP- supported TiO2 were incorporated into chitosan-based physically crosslinked hydrogels revealing significant interactions between chitosan functional groups (hydroxyls, amines and amides) with the NPs to ensure its encapsulation. These materials were evaluated as photocatalysts for the HER using water and methanol mixtures under simulated sunlight and visible light irradiation. Sample CuAuTiO2/ChTPP exhibited a maximum hydrogen generation of 1790 mu mol g(-1) h(-1) under simulated sunlight irradiation, almost 12-folds higher compared with TiO2/ChTPP. Also, the nanocomposites revealed a similar tendency under visible light with a maximum hydrogen production of 590 mu mol g(-1) h(-1) . These results agree with the efficiency of photoinduced charge separation revealed by transient photocurrent and EIS.O.R. acknowledges ANID doctoral scholarship number 21191002. H. G. thanks Ayuda RYC2022-037287-I financiada por MCIN/AEI/10.13039/501100011033 y por El FSE invierte en tu futuro. C.S. thanks FONDECYT project 121022. S.N. thanks the support of grant PID2021-123856OBI00 funded by MICIU/AEI/10.13039/501100011033 and by ERDF A way of making Europe. A.L. thanks to FONDECYT project number 1211122 and FONDAP 1522A006, for financial support for the research. D.D.D. thanks the Spanish Government for the following projects: TED2021-132847B I00/AEI/10.13039/501100011033/Union Europea NextGenerationEU/PRTR and PID2022-142118OB-I00/MCIN/AEI/10.13039/501100011033/UE. D.D.D. also thanks Nanotec, INTech, Cabildo de Tenerife and ULL for laboratory facilities.Ramírez, O.; López-Francés, A.; Baldovi, HG.; Saldías, C.; Navalón Oltra, S.; Leiva, A.; Díaz, D. (2024). Hydrogel composites based on chitosan and CuAuTiO2 photocatalysts for hydrogen production under simulated sunlight irradiation. International Journal of Biological Macromolecules. 273. https://doi.org/10.1016/j.ijbiomac.2024.13289827

Nanographite: A highly active and durable metal-free ozonation catalyst with application in natural waters

[EN] The development of metal-free heterogeneous catalysts for advanced oxidation processes has emerged as a key focus for both academia and industry. We report on research that seeks to establish a correlation between the crystallographic, physicochemical, textural, and morphological properties of a series of graphite-based solids and their activities as metal-free ozonation catalysts in aqueous media. Our findings show that nanographite (NG) outperforms traditional graphite-based solids, activated carbon and Co3O4. The enhanced activity of NG is due to defective nanosized graphitic structures with high surface areas. NG exhibits an exceptional activity, durability, and recyclability that surpasses other known catalysts. Our study employs electron spin resonance and selective quenching experiments that reveal the generation of 1O2 during catalytic ozonation. Significantly, NG shows excellent catalytic efficiency even when using natural surface river water or seawater. This study illustrates the importance of the natural properties of graphite-based materials as active and durable ozonation catalysts in water.S.N. wishes to thank the Agencia Valenciana de la Innovacio for its financial support (AVI, INNEST/2020/111). S.N. also thanks the support received from Grant PID2021-123856OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe". S.N acknowledges the funding for open access charge from "CRUE-Universitat Politecnica de Valencia". A.D. is beneficiary of a grant Maria Zambrano in Universitat Politecnica de Valencia within the framework of the grants for the retraining in the Spanish university system (Spanish Ministry of Universities, financed by the European Union, NextGeneration EU).López-Francés, A.; Bernat-Quesada, F.; Cabrero-Antonino, M.; Ferrer Ribera, RB.; Amarajothi, DM.; Garcia-Baldovi, H.; Navalón Oltra, S. (2023). Nanographite: A highly active and durable metal-free ozonation catalyst with application in natural waters. Applied Catalysis B Environmental. 336. https://doi.org/10.1016/j.apcatb.2023.12292433

Estudio de la actividad catalítica de materiales basados en grafito para la activación de ozono en procesos de tratamiento de aguas residuales empleando sistemas modelo

[ES] Los procesos convencionales de tratamiento de aguas residuales no son eficientes para la desinfección de microorganismos resistentes y para la eliminación de contaminantes orgánicos tóxicos, recalcitrantes y poco biodegradables. En este sentido, los denominados procesos de oxidación avanzada son la tecnología más adecuada para abordar este problema. Estos procesos consisten en la generación de especies con un elevado poder oxidante como son los radicales hidroxilo. Entre todos estos procesos la ozonización catalítica empleando óxidos metálicos es una alternativa económicamente viable para su implantación a escala industrial. Sin embargo, presenta una serie de inconvenientes entre los que destaca la lixiviación de metales de transición del catalizador heterogéneo al medio de reacción pudiendo causar problemas de contaminación indeseada. Como alternativa al empleo de catalizadores de ozonización catalítica basados en metales de transición está la carbocatálisis. La carbocatálisis consiste en emplear materiales carbonosos como catalizadores heterogéneos para llevar a cabo procesos tradicionalmente catalizados por metales de transición. En el presente trabajo fin de grado de emplearán materiales basados en grafito como carbocatalizadores del proceso de ozonización catalítica. En particular, se estudiarán materiales basados en grafito con distinta área superficial y distinto grado de expansión entre las láminas de grafeno que los constituyen. La actividad de los mismos se estudiará empleando disoluciones acuosas conteniendo contaminantes modelo como el ácido oxálico y el ácido 4-hidroxibenzoico. Para llevar a cabo este estudio se empleará un ozonizador a escala de laboratorio y tecnicas de caracterización y análisis como la espectroscopía UV-Vis, cromatografía iónica, cromatografía de HPLC en fase reversa, entre otras.[EN] Conventional wastewater treatment processes are not efficient for the disinfection of resistant microorganisms and for the elimination of toxic organic pollutants, recalcitrants and little biodegradable. In this sense, the so-called advanced oxidation processes are the most appropriate technology to address this problem. These processes consist in the generation of species with a high oxidizing power such as hydroxyl radicals. Among all these processes, catalytic ozonation using metal oxides is an economically viable alternative for its implementation on an industrial scale. However, it has a series of drawbacks, among which the leaching of transition metals from the heterogeneous catalyst to the reaction medium can cause problems of unwanted contamination. As an alternative to the use of catalytic ozonation catalysts based on transition metals is carbocatalysis. The carbocatalysis consists of using carbonaceous materials as heterogeneous catalysts to carry out processes traditionally catalysed by transition metals. In the present work, the students will use materials based on graphite as carbocatalysts of the catalytic ozonation process. In particular, materials based on graphite with different surface area and different degree of expansion between the graphene sheets that constitute them will be studied. The activity of the same will be studied using aqueous solutions containing model pollutants such as oxalic acid and 4-hydroxybenzoic acid. To carry out this study, an ozonizer at laboratory scale and characterization and analysis techniques such as UV-Vis spectroscopy, ion chromatography, reverse phase HPLC, among others, will be used.López Francés, A. (2019). Estudio de la actividad catalítica de materiales basados en grafito para la activación de ozono en procesos de tratamiento de aguas residuales empleando sistemas modelo. http://hdl.handle.net/10251/124450TFG

Porous Metal Organic Frameworks as Multifunctional Catalysts for Cyclohexane Oxidation

[EN] Catalysis drives the conversion of substrates to the wanted products under amenable reaction conditions. In this context, one reaction that is particularly important from the industrial point of view is cyclohexane aerobic oxidation to a mixture of the corresponding cyclohexanone and cyclohexanol. This industrial oxidation is key for the production of Nylon 6 and Nylon 6,6, two polyamides of growing production. The industrial process is clearly unsatisfactory since it is run at low cyclohexane conversions to avoid the formation of complex mixtures, difficult to isolate. The present review shows the progress made in the use of metal-organic frameworks as solid catalysts for this important reaction, with emphasis in the intrinsic activity of metal nodes, tuning of the polarity of the internal voids or incorporation of active metal nanoparticles. It is shown that using MOFs as catalysts, it is possible to reach high cyclohexane conversions, while the combined alcohol+ketone selectivity still close to the 90 % limit.AD thanks Universitat Politecnica de Valencia for Maria Zambrano support. AD also thanks University Grants Commission for the award of UGC-Assistant Professor. Financial support from the Spanish Ministry of Science and Innovation (Severo Ochoa and PID2021-126071OB-C21) and Generalitat Valenciana is gratefully acknowledged. SN thanks Grant PID2021-123856OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe".Dhakshinamoorthy, A.; López-Francés, A.; Navalón Oltra, S.; García Gómez, H. (2022). Porous Metal Organic Frameworks as Multifunctional Catalysts for Cyclohexane Oxidation. ChemCatChem. 1-14. https://doi.org/10.1002/cctc.20220103611

Graphitic Carbon Nitride as Visible-Light Photocatalyst Boosting Ozonation in Wastewater Treatment

Light can boost ozone efficiency in advanced oxidation processes (AOPs), either by direct ozone photolysis with UV light or by using a photocatalyst that can be excited with UV-Vis or solar light. The present review summarizes literature data on the combination of ozone and the g-CN photocatalyst for the degradation of probe molecules in water, including oxalic, p-hydroxybenzoic and oxamic acids as well as ciprofloxacin and parabens. g-CN is a metal-free visible-light photocatalyst based on abundant elements that establishes a synergistic effect with ozone, the efficiency of the combination of the photocatalysis and ozonation being higher than the sum of the two treatments independently. Available data indicate that this synergy derives from the higher efficiency in the generation of hydroxyl radicals due to the efficient electron quenching by O of photogenerated conduction band electrons in the g-CN photocatalyst. Given the wide use of ozonizers in water treatment, it is proposed that their implementation with g-CN photocatalysis could also boost ozone efficiency in the AOPs of real waste waters.Financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa and PIDS2021-126071OB-C21) and Generalitat Valenciana (Prometeo 2021-038) is gratefully acknowledged. S.N. thanks financial support by Agència Valenciana de la Innovació (AVI, INNEST/2020/111) project and Grant PID2021-123856OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”

Heteroepitaxial MOF-on-MOF photocatalyst for solar-driven water splitting

Assembly of different Metal-Organic Frameworks (MOFs) into hybrid MOF-on-MOF heterostructures has been established as a promising approach to develop unique synergistic performances for a variety of applications. Here we report the synthesis of MOF-on-MOF heterostructures by the epitaxial growth of MIL-88B(Fe) onto UiO-66(Zr)-NH2 nanoparticles. The face-selective design and appropriate energy band structure alignment of the selected MOF constituents have permitted its application as active heterogeneous photocatalyst for solar-driven water splitting. The composite achieves apparent quantum yields for photocatalytic overall water splitting at 400 and 450 of about 0.9 %, values that compare much favourably with previous analogous reports. Understanding of this high activity has been gained by spectroscopic and electrochemical characterization together with STEM-EDX and HRTEM-EDX measurements. This study exemplifies the possibility of developing MOF-on-MOF heterostructures with outstanding activity towards photocatalytic water splitting under solar light

Hybrid sp2/sp3 nanodiamonds as heterogeneous metal-free ozonation catalysts in water

[EN] There is a growing interest from academia and industry in metal-free heterogeneous catalysts as an alternative to current non-sustainable transition metal catalysts. Herein we report a comprehensive study on the development of hybrid nanodiamonds with a diamond core and defective graphitic shells with different sp2/sp3 ratios as metal-free ozonation catalysts. A volcano-type trend relationship between the catalytic activities with respect to the sp2/sp3 ratio was found. The most active nanodiamond pyrolysed at 1100 degrees C for 1 h exhibits a unique sp2/sp3 configuration together with an optimum amount of oxygen and nitrogen functional groups. O3 is catalytically transformed into hydroperoxyl radicals and 1O2 species. The catalytic activity of the spent hybrid nanodiamonds can be recovered by a simple annealing in an inert atmosphere that reconstitutes the defective sp2/sp3 hybrid nanodiamond. This study exemplifies the possibility of tailoring the physico-chemical properties of commercial nanodiamonds for the development of active metal-free ozonation catalysts.E.M.L. acknowledges the Generalitat Valenciana for a Ph.D. grant (ACIF/2020/267). S.N. thanks financial support by Ministerio de Ciencia, Innovati on y Universidades RTI2018-099482-A-I00 project and Agència Valenciana de la Innovació (AVI, INNEST/2020/111) project.Bernat-Quesada, F.; Vallés-García, C.; Montero-Lanzuela, E.; López-Francés, A.; Ferrer Ribera, RB.; Baldovi, HG.; Navalón Oltra, S. (2021). Hybrid sp2/sp3 nanodiamonds as heterogeneous metal-free ozonation catalysts in water. Applied Catalysis B Environmental. 299:1-11. https://doi.org/10.1016/j.apcatb.2021.12067311129

Regulatory role of PI3K-Akt on the release of IL-1β in peritoneal macrophages from the ascites of cirrhotic patients

© 2014 British Society for Immunology. This manuscript version is made available under the CC-BY-NC 4.0 License.http://creativecommons.org/licenses/by-nc/4.0/. This document is the Published version of a Published Work that appeared in final form in American Journal of Clinical and Experimental Immunology. To access the final edited and published work see https://doi.org/10.1111/cei.12428Great effort has been paid to identify novel targets for pharmaceutical intervention to control inflammation associated with different diseases. We have studied the effect of signalling inhibitors in the secretion of the proinflammatory and profibrogenic cytokine interleukin (IL)-1β in monocyte-derived macrophages (M-DM) obtained from the ascites of cirrhotic patients and compared with those obtained from the blood of healthy donors. Peritoneal M-DM were isolated from non-infected ascites of cirrhotic patients and stimulated in vitro with lipopolysaccharide (LPS) and heat-killed Candida albicans in the presence or absence of inhibitors for c-Jun N-terminal kinase (JNK), mitogen-activated protein kinase kinase 1 (MEK1), p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). The IL1B and CASP1 gene expression were evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The expression of IL-1β and caspase-1 were determined by Western blot. IL-1β was also assayed by enzyme-linked immunosorbent assay (ELISA) in cell culture supernatants. Results revealed that MEK1 and JNK inhibition significantly reduced the basal and stimulated IL-1β secretion, while the p38 MAPK inhibitor had no effect on IL-1β levels. On the contrary, inhibition of PI3K increased the secretion of IL-1β from stimulated M-DM. The activating effect of PI3K inhibitor on IL-1β release was mediated mainly by the enhancement of the intracellular IL-1β and caspase-1 content release to the extracellular medium and not by increasing the corresponding mRNA and protein expression levels. These data point towards the role of MEK1 and JNK inhibitors, in contrast to the PI3K-protein kinase B inhibitors, as potential therapeutic tools for pharmaceutical intervention to diminish hepatic damage by reducing the inflammatory response mediated by IL-1β associated with liver failure

Development of Decellularized Oviductal Hydrogels as a Support for Rabbit Embryo Culture

[EN] The oviducts (fallopian tubes in mammals) function as the site of fertilization and provide necessary support for early embryonic development, mainly via embryonic exposure to the tubal microenvironment. The main objective of this study was to create an oviduct-specific extracellular matrix (oviECM) hydrogel rich in bioactive components that mimics the native environment, thus optimizing the developmental trajectories of cultured embryos. Rabbit oviducts were decellularized through SDS treatment and enzymatic digestion, and the acellular tissue was converted into oviductal pre-gel extracellular matrix (ECM) solutions. Incubation of these solutions at 37 degrees C resulted in stable hydrogels with a fibrous structure based on scanning electron microscopy. Histological staining, DNA quantification and colorimetric assays confirmed that the decellularized tissue and hydrogels contained no cellular or nuclear components but retained important components of the ECM, e.g. hyaluronic acid, glycoproteins and collagens. To evaluate the ability of oviECM hydrogels to maintain early embryonic development, two-cell rabbit embryos were cultured on oviECM-coated surfaces and compared to those cultured with standard techniques. Embryo development was similar in both conditions, with 95.9% and 98% of the embryos reaching the late morula/early blastocyst stage by 48 h under standard culture and oviECM conditions, respectively. Metabolomic analysis of culture media in the presence or absence of embryos, however, revealed that the oviECM coating may include signalling molecules and release compounds beneficial to embryo metabolism.This study was supported by Instituto de Salud Carlos III (PI17/01039-CP19/00149 [Irene Cervello]), Ministry of Economy, Industry and Competitiveness (AGL2017-85162-C2-1-R [Francisco Marco], BES-2015-072429 [Ximo Garcia]), Ministry of Science, Innovation and Universities (FPU18/06327 [Emilio Frances]) and Generalitat Valenciana (PROMETEO/2018/137 [Irene Cervello, Lucia de Miguel], ACIF/2017/118 [Sara Lopez]). The proteomics laboratory is a member of ProteoRed, PRB3, and is supported by grant PT17/0019 of the State Plan I+D+i 2013-2016, funded by Instituto de Salud Carlos III and European Regional Development Fund.Francés-Herrero, E.; De Miguel-Gómez, L.; López-Martínez, S.; Campo, H.; Garcia-Dominguez, X.; Diretto, G.; Faus, A.... (2021). Development of Decellularized Oviductal Hydrogels as a Support for Rabbit Embryo Culture. Reproductive Sciences. 28(6):1644-1658. https://doi.org/10.1007/s43032-020-00446-6S1644165828

El Programa de Acción Tutorial de la Facultad de Económicas: la comunicación y la formación como factores de éxito

Esta comunicación se enmarca dentro de la participación de los tutores del Programa de Acción Tutorial de la Facultad de Económicas (PATEC) en el Programa Redes-I3CE de Investigación en docencia universitaria. Este curso, el trabajo de la Red de tutores del PATEC se ha centrado en analizar lo que hacen otras universidades en el ámbito de la formación para mejorar la cualificación de los tutores y en estudiar cómo funciona el programa alumno-tutor como herramienta intermedia de comunicación entre el profesorado y los estudiantes. En esta comunicación se recogerán los principales resultados obtenidos de este análisis. Además, para abordar el problema de la comunicación se realizará una encuesta al alumnado tutorizado cuyos resultados permitirán comprender los factores que la limitan para proceder al diseño de nuevas propuestas que mejoren este aspecto esencial del programa