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Efficient CO2 photoreduction to CO with >70% product selectivity over a periodic mesoporous organosilica-based heterogeneous catalyst containing molecular cobalt phthalocyanine units.

A novel cobaloxime–PMO hybrid material as an efficient hydrogen evolution catalyst under photocatalytic conditions.

A versatile and facile strategy based on an inverse electron demand Diels–Alder reaction between 5-norbornen-2-yltriethoxysilane and a tetrazine derivative has been established for the synthesis of a new triethoxysilane precursor containing dipyridylpyridazine units. Such a precursor has been incorporated into the mesostructure of an ethylene-bridged periodic mesoporous organosilica (PMO) material through a one-pot synthesis via a co-condensation method. Upon attachment of Ru- and Ir-complexes to the pendant N-chelating heterocyclic ligands, the resulting decorated PMOs have acted as photosensitizers in artificial photosynthetic systems. The deposition of Pt on these PMOs has allowed us to obtain efficient photocatalytic materials for the hydrogen evolution reaction as a result of electron transfer from the light harvesting Ru- and Ir-complexes to the supported Pt nanoparticles through methyl viologen as an electron relay. They have exhibited total turnover number values of 573 and 846, respectively, under visible light irradiation. The role played by each component and the stability of the photocatalytic systems have been discussed. The present approach paves the way to the synthesis of different materials with coordination sites capable of forming surface complexes to be applied as sensitizers and catalysts.

The presence of potent organic endocrine-disrupting chemicals (EDCs) in natural aquifers can have adverse impacts on public health and the environment. 4-nonylphenol, one such EDC, can be efficiently removed from water by adsorption onto a clayey material. In this work, we created an effective sorbent for this purpose by using co-precipitation and subsequent ion-exchange to intercalate the organic anion deoxycholate into a Mg/Al hydrotalcite. Intercalating deoxycholate ions increased the organophilicity of the hydrotalcite surface. The solid was used to adsorb 4-nonylphenol at different pollutant concentrations and temperatures. The adsorption process was subjected to a kinetic study. Based on the results, the EDC was adsorbed by chemisorption. In addition, based on the equilibrium isotherms used for the process, the Freundlich model was the most accurate in reproducing the adsorption of 4-nonylphenol onto deoxycholate-intercalated hydrotalcite.

This paper presents a novel approach to create bifunctional periodic mesoporous organosilicas containing thiol and sulfonic acid groups (SHm/SO3Hn@PMO) by co-condensation reactions of an own design...

A new heterogeneous catalyst has been synthesized by immobilization of a copper complex on dipyridyl-pyridazine functionalized periodic mesoporous organosilica (dppz-vPMO). This ordered support was first prepared by a co-condensation reaction between vinyltriethoxysilane and 1,2-bis(trimethoxysilyl)ethane and further post-functionalized through a hetero Diels-Alder reaction with 3,6-di-2-pyridyl-1,2,4,5-tetrazine. Techniques such as XRD, N

A biomimetic model complex of the [FeFe]-hydrogenase active site (FeFeOH) with an ethylene bridge and a pendant hydroxyl group has been synthesized, characterized and evaluated as catalyst for the light-driven hydrogen production. The interaction of the hydroxyl group present in the complex with 3-isocyanopropyltriethoxysilane provided a carbamate triethoxysilane bearing a diiron dithiolate complex (NCOFeFe), thus becoming a potentially promising candidate for anchoring on heterogeneous supports. As a proof of concept, the NCOFeFe precursor was anchored by a grafting procedure into a periodic mesoporous organosilica with ethane bridges (EthanePMO@NCOFeFe). Both molecular and heterogenized complexes were tested as catalysts for light-driven hydrogen generation in aqueous solutions. The photocatalytic conditions were optimized for the homogenous complex by varying the reaction time, pH, amount of the catalyst or photosensitizer, photon flux, and the type of light source (light-emitting diode (LED) and Xe lamp). It was shown that the molecular FeFeOH diiron complex achieved a decent turnover number (TON) of 70 after 6 h, while NCOFeFe and EthanePMO@NCOFeFe had slightly lower activities showing TONs of 37 and 5 at 6 h, respectively.

Embargado hasta 15/02/2023 The assembly of atomically dispersed iron–nitrogen (FeN4) sites into graphitic structures is a promising approach for sustainable production of bifunctional electrocatalysts for the oxygen electroreduction (ORR) and oxygen evolution (OER) reactions. In addition, single-atom FeN4 sites at the edges of carbon substrates provide higher electrocatalytic performance than those in plane. Unfortunately, the conventional high-temperature pyrolysis method does not allow the generation of edge-enriched FeN4 single-atom sites. Herein, a novel low-temperature and solvent-free mechanochemical synthesis based on the use of dipyridylpyridazine (dppz) functionalized multilayer graphene as a starting material is proposed for precisely engineered location of these FeN4 active sites at the edges. After careful characterization of these dppz-based materials, the ORR and OER electrocatalytic performance was investigated, demonstrating the efficient formation of FeN4 sites at the edges as well as their excellent bifunctional behavior for the ORR and OER. This work paves the way for the development of sustainable approaches for the generation of edge-enriched FeN4 single atom sites on multilayer graphene structures.

Oleate ion was intercalated into a hydrotalcite obtained using a conventional precipitation method and an alternative, novel method involving microwave-assisted ion exchange. The latter method gave a more crystalline hydrotalcite with better textural properties than the former. The spacing between layers in the hydrotalcites was used to epoxidize the double bond in oleate ion. X-ray diffraction patterns revealed that the layered structure of the hydrotalcites was not altered by the reaction. The epoxidation of oleate ion with m-chloroperbenzoic acid (mCPBA) was monitored using Raman spectroscopy. The results of this work testify to the high potential of hydrotalcites as molecular reactors for reactions in confined spaces.

Different MgAl mixed oxides with a Mg/Al ratio of 2 were obtained through calcination of the corresponding hydrotalcites at 450 °C and tested for MPV reaction of benzaldehyde with 2-butanol. The influence of several synthetic parameters (such as co-precipitation in the presence of Pluronic P123 or homogeneous precipitation in the presence of urea in the medium) on catalytic performance was studied. The use of urea led to a decrease in surface area as compared to conventional precipitation method (125 m2/g and 201 m2/g, respectively) but an increase in surface basicity (7.3 µmol CO2/m2 and 4.3 µmol CO2/m2, respectively). Utilization of Pluronic 123 increases surface area (183 m2/g) though basicity is hardly affected (4.2 µmol CO2/m2). All the catalysts showed a high conversion and high selective to the desired product, observing a relationship between the density of basic sites and the catalytic activity. All in all, the solid exhibiting the highest benzyl alcohol yield was that synthesized in the presence of urea (labelled as HT-U-450), with a rate of 2.05 mmol benzyl alcohol/gcat × min.

The adsorption of S-metolachlor herbicide from aqueous solution by benzenesilica materials was studied. The materials were synthesized with 1,4-bis(triethoxysilyl)benzene as organosilica precursor and Brij 76 and Pluronic P123 as surfactants. Additionally, 1,3,5-triisopropylbenzene (TPB) was used as porogen to produce microporosity. Those materials obtained by Brij-76 and P123 showed well-structured ordering. However, a disordered microporous benzenesilica material was obtained in presence of P123 and TPB. All materials proved to be efficient adsorbents for S-metolachlor. Among them, the material synthesized with Brij 76 showed the highest adsorption capacity due to its ordered structure and, mainly, to its higher proportion of mesopores.

Organic–inorganic layered double hydroxides (LDHs) were obtained by using a microwave-assisted method to intercalate cholate or deoxycholate ion into an Mg, Al mixed LDH. Based on the X-ray diffraction and Raman spectra for the resulting LDHs, a treatment time of only 1 h sufficed to ensure complete intercalation of the organic anions. This makes the proposed synthetic method more expeditious than existing alternatives for the same purpose. Based on the baseline spacing for the organo-LDHs, the organic anions were intercalated with no cross-over between their molecular chains. The interlayer distance of the solids was confirmed by high-resolution transmission electron micrographs (HR-TEM). As revealed by thermogravimetric monitoring measurements, and confirmed by Raman spectra, the decomposition temperature for the LDHs increased considerably upon intercalation of the organic anion.

A global hydrogen economy could ensure environmentally sustainable, safe and cost-efficient renewable energy for the 21st century. Solar hydrogen production through artificial photosynthesis is a key strategy, and the activity of natural hydrogenase metalloenzymes an inspiration for the design of synthetic catalyst systems. [FeFe]-hydrogenase enzymes, present in anaerobic bacteria and green algae, are the most efficient class of biological catalysts for hydrogen evolution. The enzymes operate in an aqueous environment, utilizing electrons that ultimately stem from photosynthesis as the only energy source. Functional synthetic models of the [FeFe]-hydrogenase enzyme active site have garnered intense interest as potential catalysts for the reduction of protons to molecular hydrogen. Herein, we take an extensive journey through the field of biomimetic hydrogenase chemistry for lightdriven hydrogen production. We open with a brief presentation of the structure and redox mechanism of the natural enzyme. Synthetic methodologies, structural characteristics, and hydrogen generation metrics relevant to the synthetic diiron catalysts ([2Fe2S]) are discussed. We first examine multicomponent photocatalysis systems with the [2Fe2S] cluster, followed by photosensitizer-[2Fe2S] dyads and molecular triads. Finally, strategies for the incorporation of [2Fe2S] complexes into supramolecular assemblies, semiconductor supports, and hybrid heterogeneous platforms are laid out. We analyze the individual properties, scope, and limitations of the components present in the photocatalytic reactions. This review illuminates the most useful aspects to rationally design a wide variety of biomimetic catalysts inspired by the diiron subsite of [FeFe]-hydrogenases, and establishes design features shared by the most stable and efficient hydrogen producing photosystems. (C) 2021 The Author(s). Published by Elsevier B.V.

The development of effective, environmentally friendly catalysts for the Baeyer–Villiger reaction is becoming increasingly important in applied catalysis. In this work, we synthesized a 3D composite consisting of silica spheres coated with Mg/Al hydrotalcite with much better textural properties than its 2D counterparts. In fact, the 3D solid outperformed a 2D-layered hydrotalcite as catalyst in the Baeyer–Villiger reaction of cyclic ketones with H2O2/benzonitrile as oxidant. The 3D catalyst provided excellent conversion and selectivity; it was also readily filtered off the reaction mixture. The proposed reaction mechanism, which involves adsorption of the reactants on the hydrotalcite surface, is consistent with the catalytic activity results.

The necropolis of Camino Viejo de Almodovar (Cordoba, southern Spain) is one of several burial grounds dating from Roman Corduba. In this work, we used various optical and laser techniques, including optical microscopy, scanning electron microscopy in combination with energy-dispersive spectroscopy and micro-Raman (μ-Raman) spectroscopy to identify the pigments used in wall painting fragments unearthed in excavations at the site. The results thus obtained were confirmed and supplemented by using X-ray fluorescence spectroscopy. The experimental evidence provided by these techniques allowed us to identify the materials used to obtain the pigments, namely: lime, hematite, cinnabar, goethite, Egyptian blue, coal and green earth.

Objective To compare length of stay (LOS) in neonatal care for babies born extremely preterm admitted to networks participating in the International Network for Evaluating Outcomes of Neonates (iNeo). Study design Data were extracted for babies admitted from 2014 to 2016 and born at 24 to 28 weeks of gestational age (n = 28 204). Median LOS was calculated for each network for babies who survived and those who died while in neonatal care. A linear regression model was used to investigate differences in LOS between networks after adjusting for gestational age, birth weight z score, sex, and multiplicity. A sensitivity analysis was conducted for babies who were discharged home directly. Results Observed median LOS for babies who survived was longest in Japan (107 days); this result persisted after adjustment (20.7 days more than reference, 95% CI 19.3-22.1). Finland had the shortest adjusted LOS (−4.8 days less than reference, 95% CI –7.3 to −2.3). For each week's increase in gestational age at birth, LOS decreased by 12.1 days (95% CI –12.3 to −11.9). Multiplicity and male sex predicted mean increases in LOS of 2.6 (95% CI 2.0-3.2) and 2.1 (95% CI 1.6-2.6) days, respectively. Conclusions We identified between-network differences in LOS of up to 3 weeks for babies born extremely preterm. Some of these may be partly explained by differences in mortality, but unexplained variations also may be related to differences in clinical care practices and healthcare systems between countries.

Background Very preterm infants are at high risk of death or severe morbidity. The objective was to determine the significance of severe congenital heart defects ( CHDs ) for these risks. Methods and Results This cohort study included infants from 10 countries born from 2007–2015 at 24 to 31 weeks’ gestation with birth weights CHDs were defined by International Classification of Diseases, Ninth Revision ( ICD‐9 ) and Tenth ( ICD‐10 ) codes and categorized as those compromising systemic output, causing sustained cyanosis, or resulting in congestive heart failure. The primary outcome was in‐hospital mortality. Secondary outcomes were neonatal brain injury, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity. Adjusted and propensity score–matched odds ratios ( ORs ) were calculated. Analyses were stratified by type of CHD , gestational age, and network. A total of 609 (0.77%) infants had severe CHD and 76 371 without any malformation served as controls. The mean gestational age and birth weight were 27.8 weeks and 1018 g, respectively. The mortality rate was 18.6% in infants with CHD and 8.9% in controls (propensity score–matched OR , 2.30; 95% CI , 1.61–3.27). Severe CHD was not associated with neonatal brain injury, necrotizing enterocolitis, or retinopathy of prematurity, whereas the OR for bronchopulmonary dysplasia increased. Mortality was higher in all types, with the highest propensity score–matched OR (4.96; 95% CI, 2.11–11.7) for CHD causing congestive heart failure. While mortality did not differ between groups at OR for mortality in infants with CHD increased to 10.9 (95% CI, 5.76–20.70) at 31 weeks’ gestational age. Rates of CHD and mortality differed significantly between networks. Conclusions Severe CHD is associated with significantly increased mortality in very preterm infants.

Desde la inclusión de España en la Declaración de Bolonia, cuyo objetivo es reformar el sistema universitario a través del Espacio Europeo de Educación Superior (EEES), el alumno adquiere un papel de liderazgo en el proceso de enseñanza-aprendizaje. Con el fin de promover la autonomía entre los estudiantes en el proceso de capacitación, el uso de las Tecnologías de la Información y la Comunicación (TIC) es cada vez más común. Entre ellos, el e-learning con aplicaciones móviles tiene un gran potencial para fortalecer el proceso de aprendizaje, dado su uso popular entre los estudiantes universitarios. Esto se debe principalmente a que estas herramientas tienen una variedad de ventajas sobre los métodos tradicionales, como conferencias magistrales, entre los que cabe citar, entre otras, el que permiten la comunicación profesor-estudiante más allá de los espacios tradicionales, rompiendo las barreras o límites de espacio y tiempo, que favorecen la autonomía (autoaprendizaje) del estudiante o que permiten la presentación de la información en una gran variedad de formas y lenguajes. Además, son fácilmente conectables a las redes sociales, lo que hace que el proceso de aprendizaje sea más atractivo, más accesible y más cooperativo. Con el propósito de aumentar la motivación de los estudiantes, en este trabajo, se diseñó y desarrolló una aplicación móvil, en la que se han virtualizado tres laboratorios pertenecientes a la Facultad de Ciencias (Biología y Química) y la Escuela Politécnica Superior (Física de Ingeniería Mecánica) de la Universidad de Córdoba. En cada uno de los tres laboratorios, los estudiantes pueden acceder a información multimedia correspondiente a diversos materiales, equipos, videos, enlaces, laboratorios virtuales, así como una explicación de algunas sesiones prácticas. Para el desarrollo de diferentes escenarios, se han utilizado imágenes panorámicas de 360º, que se han realizado utilizando técnicas HDR (High Dynamic Range). La plataforma elegida para el desarrollo fue Android, debido al uso mayoritario de este sistema operativo en dispositivos móviles entre los estudiantes. Conviene destacar que este tipo de e-learning facilita a los estudiantes el acceso a materiales relacionados con las materias prácticas en estudio que son muy importantes en la enseñanza de las ciencias. Además, se familiarizan más con los términos técnicos de una manera interactiva, más entretenida y eficiente, mejorando el grado de motivación y la participación del estudiante en los temas en estudio. Esto conduce a una mayor asimilación de conocimientos y habilidades. Para verificar esto, para cada laboratorio, dividimos a los estudiantes en un grupo sin acceso a la aplicación (grupo de control) y otro (grupo de prueba) con acceso. Llevamos a cabo una serie de cuestionarios con los grupos de prueba usando la plataforma basada en juegos "Kahoot!" y Google Forms. Los cuestionarios intentaron aclarar el grado de aceptación de la herramienta, el impacto en el aprendizaje de los temas en estudio y la identificación de posibles áreas de mejora. En general, los estudiantes del grupo de prueba encontraron la herramienta muy interesante y les ayudó a mejorar sus puntuaciones en comparación con el grupo de control. No se aprecia una distinción clara entre los estudiantes de diferentes materias. Entre los aspectos a mejorar, se encuentra el contenido relativamente limitado de esta primera versión. Además, la evaluación se realizó con un único grupo control y un grupo de prueba en cada materia, lo que limita su potencial para extraer conclusiones definitivas. En el futuro, se realizarán más cargas y pruebas de contenido en diferentes cursos para evaluar los beneficios del aprendizaje de ciencias mediante esta aplicación. Since the inclusion of Spain in the Bologna Declaration, whose objective is to reform the university system through the European Higher Education Area (EHEA), the student acquires a leading role in the teaching-learning process. In order to promote autonomy among the students in the training process, the use of Information and Communication Technologies (ICT) is increasingly common. Among them, e-learning using mobile apps has a great potential to strengthen the learning process given its popular use among university students. This is mostly because these tools have assorted advantages over traditional methods, e.g. magisterial lectures, such as ubiquitous access, possibility to update and increase content, self-learning, etc. Moreover, they are easily linkable to social media, thus making the learning process more attractive, more easily accessible and more cooperative. For the purpose of increasing student motivation, in this work, a mobile application has been designed and developed, in which three laboratories, belonging to the faculties of Sciences (Biology and Chemistry) and Engineering, have been virtualized. In each of the three laboratories, the students can access to some multimedia information corresponding to various materials and equipment, videos, links, virtual laboratories as well as an explanation of some practical sessions. For the different scenarios development, 360º panoramic pictures have been used, which have been made using HDR (High Dynamic Range) techniques. The platform chosen for the development was Android, due to the majority use of this operating system on mobile devices among the students. It is good to notice that this type of e-learning facilitates students the accessibility to materials related to the practical subjects under study which are very important in science teaching. Furthermore, they become more familiar with technical terms in an interactive, more entertaining and efficient manner, improving the motivation degree and the student's involvement in the subjects under study. This leads to a greater assimilation of knowledge and skills. To verify this, for each laboratory, we divided the students in a group without access to the app (control group) and another one (testing group) with access. We conducted a series of questionnaires with the testing groups using the game-based platform “Kahoot!” and Google Forms. The questionnaires intended to enlighten the degree of acceptance of the tool, the impact on learning of the subjects under study and the identification of potential areas of improvement. Generally, the testing group students found the tool very interesting and helped them improving their scores compared to the control group. No clear distinction between students of different subjects was appreciated. A limited content in this first version was major drawback. Moreover, this evaluation has been conducted only with one control and one testing group of each subject, thus limiting its potential to extract definite conclusions. Further content upload and testing on different courses will be done in the future to evaluate the benefits of science learning using this app.

This paper reports results of ongoing research on wallpaintings in the Roman villa of Fuente Alamo (Puente Genil, Southern Spain). Wall decoration vestiges from an older building stage and a newer one subsequently erected on it were examined. The lack of information about wallpaintings in this villa led us to study the materials constituting the mortars and pigments, and to elucidate the painting technique used in order to facilitate optimal restoration. Paint layers exhibited a wide variety of colours but mainly red, ochre, blue, green, black and white. Pigments included high-quality materials such as Egyptian blue and other, more common elements of the Roman palette such as red and yellow earths, and lime white. The materials were characterized by X-ray diffraction and Raman microspectroscopy.

A diiron [FeFe]-hydrogenase model complex tethered with a maleimide group, FeFe1, was covalently grafted on the pore surface of a periodic mesoporous organosilica with thiol groups (SH-PMO) to form an efficient heterogeneous hydrogen (H-2)-evolution catalyst FeFe1@PMO. The coordination structure of the FeFe1 complex and the ordered pore structure were almost completely preserved even after immobilization of FeFe1 on SH-PMO. The FeFe1@PMO promoted photocatalysis for H-2 evolution in water containing a photosensitizer [Ru(bpy)(3)](2+), with a turnover number (TON) of 310 over 120 min. The TON was greater than those of an analogous homogeneous FeFe1 catalyst (TON=180) and conventional diiron complexes immobilized on solid supports (TON=6-18). The increased TON for FeFe1@PMO compared to the homogeneous FeFe1 was attributed to the improvement in the stability of the FeFe1 complex by immobilization on the pore surface of SH-PMO. A [Ru(bpy)(3)](2+) photosensitizer tethered with a maleimide (Ru1) was prepared and co-immobilized on FeFe1@PMO to form an all-solid-state photocatalyst FeFe1-Ru1@PMO. FeFe1-Ru1@PMO evolved H-2 without the additional [Ru(bpy)(3)](2+) photosensitizer, suggesting efficient photoinduced electron transfer from the immobilized Ru1 to the immobilized FeFe1.

Wallpainting fragments from the Caliphal Baths of Cordoba, Spain, were studied in this work for the first time. X-ray diffraction (XRD) and Raman microspectroscopy allowed the chemical nature of th...

The analysis by Raman microscopy of several wallpainting fragments found at an archaeological site in Fuente Tojar and in the Roman villa of Priego de Cordoba, both in southern Spain, revealed that the most abundant colours in them were obtained from the usual pigments of the time. Thus, red corresponded to red ochre, which consisted of hematite mainly. Also, yellow came from yellow ochre (goethite), blue from Egyptian blue, and grey hues were obtained from mixtures of coal and calcite occasionally also containing gypsum. The components of some pigments were confirmed by X-ray diffraction spectroscopy. The two spectroscopic techniques were additionally used to examine the mortars and the preparatory layer present in the fragments.

Fragments of a wall painting from a High Roman Empire building in Cordoba, southern Spain, were examined. The aim was not to extract archaeological information, but rather to precisely identify the materials from which the pigments were obtained and how they were applied. The mortar receiving the pigments was also analysed. Determinations were done by using X-ray fluorescence (XRF), micro-Raman (μ-Raman) and Fourier transform infrared (FT-IR) spectroscopies, X-ray diffraction (XRD) and scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM–EDS). The XRF technique allowed chemical elements to be identified and, in combination with SEM–EDS, their spatial distribution in the fragments to be elucidated. Similarly, μ-Raman spectroscopy and XRD allowed the chemical species in the mortar to be identified. The pigments found were typical of the Roman colour palette used in Hispania and included various types of ochre (yellow and red), mixtures containing green earths, white (calcium carbonate), black (carbon) and precious materials such as cinnabar and Egyptian blue. The mortar was found to have been prepared in the traditional manner from limestone and sand. The pigments were applied in solution or suspended in lime water, a technique that was latter named mezzo fresco. By exception, cinnabar and Egyptian blue were applied with the secco technique and the aid of an organic binder. Some fragments contained several paint layers. In any case, the paint was invariably applied directly on an unprimed wall.

Silica microspheres obtained by using the Stober method were coated with a 2:1 Mg/Al hydrotalcite to prepare various composites. The composites, labelled SiO2@HT, were characterized by using instrumental techniques including scanning and transmission electron microscopies, and micro-Raman, X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) spectroscopies. The microspheres were about 0.5 μm in diameter and success in their coating with hydrotalcite was strongly pH-dependent. Thus, a pure SiO2@HT composite could only be obtained by using pH 9, at which the microspheres were coated with horizontally stacked layers of hydrotalcite.

Highly ordered thiol-ethylene bridged Periodic Mesoporous Organosilicas were synthesized directly from a homemade thiol-functionalized bis-silane precursor. These high surface area materials contain up to 4.3 mmol/g sulfur functions in the walls and can adsorb up to 1183 mg/g mercury ions. Raman spectroscopy reveals the existence of thiol and disulfide moieties. These groups have been evaluated by a combination of Raman spectroscopy, Ellman’s reagent and elemental analysis. The adsorption of mercury ions was evidenced by different techniques, including Raman, XPS and porosimetry, which indicate that thiol groups are highly accessible to mercury. Scanning transmission electron microscopy combined with EDX showed an even homogenous distribution of the sulfur atoms throughout the structure, and have revealed for the first time that a fraction of the adsorbed mercury is forming thiolate nanocrystals in the pores. The adsorbent is highly selective for mercury and can be regenerated and reused multiple times, maintaining its structure and functionalities and showing only a marginal loss of adsorption capacity after several runs.

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min-1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency.