Examinando por Autor "Hierro, Isabel del"
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Ítem Analyzing lime mortars from a historic construction in Magán (Toledo, Spain): Insights into mineralogy and firing temperatures(Elsevier, 2024-12) Hierro, Isabel del; Reyes-Téllez, Francisco; Herrera, Raquel; Lillo, Javier; Ortiz-Bustos, Josefa; Pérez-Cortes, Yolanda; Polo-Romero, Alberto; Viñuales-Ferreiro, GonzaloMortar samples from the remains of a nearly vanished structure in the village of Magán (Toledo, Spain) have been investigated. Their mineralogical and chemical composition have been analyzed to understand the building technology of their historical period and the functionality of the original structure. Furthermore, a wide range of characterization techniques has been employed in the investigation regarding the amount of information they can provide and assess their effectiveness in the field. Chemical characterization of the mortar samples has been performed by XRD and XRF and completed with TGA studies. FTIR and Raman Spectroscopy, together with 28Si and 27Al-MAS-NMR and Microscopy Studies complete these characterization studies. Although the samples possess similar composition, since the predominant mineralogy is quartz, feldspars, and phyllosilicates, the differences discovered let us establish a relationship between chemical data and petrographic mineralogical data, and the source of materialsÍtem Innovative ternary composite photocatalyst: BiOCl/Bi12O17Cl2/Bi2O3 for sustainable water remediation(Elsevier, 2024-07-01) Pérez del Pulgar, Helena; Ortiz-Bustos, Josefa; Torres-Pardo, Almudena; Parras, Marina; Hierro, Isabel del; Pérez, YolandaThe presence of pollutants in aquatic environments is causing severe health effects on both humans and animals. To address this issue, it has become crucial to develop more efficient and environmentally friendly photocatalysts for the removal of persistent pollutant mixtures from water. In this context, photocatalysts containing more than two bismuth-based materials have rarely been explored for water remediation. With this in mind, we propose an innovative ternary composite, BiOCl-1/Bi12O17Cl2/Bi2O3, as a potentially sustainable visible light-active photocatalyst. Firstly, bismuth oxychloride has been prepared in the presence of ionic liquid, leading to the formation of BiOCl-1 with highly reactive {1 1 0} facets. Subsequently, the construction of the ternary composite has been accomplished using a facile and soft hydrothermal approach. The as-prepared BiOCl-1/Bi12O17Cl2/Bi2O3 composite has been successfully used in degrading binary mixtures of contaminants (i.e. ciprofloxacin, methylparaben or methyl orange), achieving an improved visible-light photocatalytic activity compared to single BiOCl-1 and other previously reported bismuth-based photocatalysts. In addition, the photocatalytic mechanism and degradation pathways have been elucidated through scavenger and electrochemical experiments, as well as chromatography-mass spectrometry (LC-MS) analysis, respectivelyÍtem Prolinate-based heterogeneous catalyst for Knoevenagel condensation reaction: insights into mechanism reaction using solid-state electrochemical studies(Elsevier, 2022) Ortiz-Bustos, Josefa; Cruz, Paula; Pérez, Yolanda; Hierro, Isabel delThe carbon-carbon bond formation is essential to producing relevant organic compounds that exhibit pharmacological and biological properties. In this regard, Knoevenagel and multicondensation reactions have been employed to test the acid-base cooperativity of functionalized mesoporous silica nanoparticles with L-prolinate based groups (Prol-MSN) in comparison with choline hydroxide fragments (Chol-MSN). Thus, Prol-MSN material has shown to be a promising heterogeneous organocatalyst for condensation reactions. The use of electrochemical sensor techniques allowed through cyclic and differential pulse voltammetry studies a better understanding of the catalytic mechanism of Knoevenagel reaction for the Prol-MSN material, including the role of silanol surface groups and protic solvents.Ítem Síntesis y estudio electroquímico de complejos de niobio incorporando ligandos ansa-ciclopentadienilo asimétricos(2014-01-29) Antiñolo, Antonio; Expósito, Teresa; Hierro, Isabel del; Lucas, Dominique; Mugnier, Yves; Orive, Irache; Otero, Antonio; Prashar, SanjivSe han preparado los complejos asimétricos bicloruro de ansa-nioboceno(IV): [Nb{Me2Si(eta5-C5Me4)(eta5-C5H3R)}Cl2] (R = H (1a), Me (2a), SiMe3 (3a), Pri (4a), PPh2 (5a)). 1a-5a se han caracterizado mediante los correspondientes espectros de RSE, IR y análisis elemental. Los estudios electroquímicos de estos derivados nos han permitido evaluar los potenciales de oxidación y reducción que se han comparados con complejos análogos no ansa. También han sido sintetizados nuevos complejos niobocenos [Nb(eta5-C5H4R)2}Cl2] (R = Pri (6a), PPh2 (7a)) y estudiados electroquímicamente.Ítem Synthesis of cationic niobocene imido derivatives(2014-01-29) Hierro, Isabel del; Fajardo, Mariano; Garcés, Andrés; Gómez-Ruiz, Santiago; Pérez, Yolanda; Prashar, Sanjiv; Antiñolo, Antonio; Otero, Antonio; López-Mardomingo, CarmenFollowing from our previous work in the synthesis and reactivity of niobium imido complexes,1 we have studied the preparation of cationic derivatives. The reduction of [Nb(=NPh)(eta5-C5H4SiMe3)2Cl] gives the short-lived niobocene(IV) radical [Nb(=NPh)(eta5-C5H4SiMe3)2. which was rapidly oxidized to the niobocene(V) cationic species [Nb(=NPh)(eta5-C5H4SiMe3)2(L)]+ (L = CO, ButNC) by the reaction with [Fe(eta5-C5H5)2][BPh4]. In a similar manner, the ansa-niobocene compound [Nb(=NBut){Me2Si(eta5-C5Me4)(eta5-C5H4)}(ButNC)][BPh4] was synthesized. However, in the attempted reduction of [Nb(=NBut){Me2Si(eta5-C5H4)2}Cl], the expected radical species was not observed. Instead the niobocene (V) imido dimer product was identified. The reaction with H2 and I2 gave [Nb(=NBut){Me2Si(eta5-C5H4)2}H] and [Nb(=NBut){Me2Si(eta5-C5H4)2}I], respectively.Ítem Tuning adsorption capacities of hybrid mesoporous silica nanospheres and adsorption mechanism study for sulfamethoxazole and diclofenac removal from water(Elsevier, 2024-03-15) Ortiz-Bustos, Josefa; Soares, Sofía F.; Pérez del Pulgar, Helena; Pérez, Yolanda; Gómez-Ruiz, Santiago; Daniel-da-Silva, Ana Luísa; Hierro, Isabel delThe functionalization of mesoporous silica nanospheres and mesoporous hybrid core–shell magnetic silica nanospheres has been carried out through post-synthetic procedures, and these materials have been tested as adsorbents for the removal of sulfamethoxazole (SMX) and diclofenac (DF) from water. The effects of the silica material and the types of functionalities anchored on the silica surface have been investigated. Additionally, the unreacted silanol groups on the silica surface have been capped with hydrophobic trimethylsilyl groups to modify the hydrophilic-hydrophobic properties of the materials. The materials have been characterized by textural, spectroscopic, and microscopic techniques. The maximum adsorption capacity and kinetics of adsorption were determined using adsorption and kinetic theoretical models. The experimental results indicate that both the surface area and the presence of specific functionalities on the silica surface, including zwitterionic groups like hydroxide choline and methyl p-toluene sulfonate choline, have a significant impact on the material's adsorption capacity. The adsorption studies revealed that the highest adsorption capacity (qt) for DF (80.7 mg L-1) and SMX (27.2 mg L-1) was achieved with PTS-Chol-MSN, which consists of mesoporous silica nanospheres possessing a larger surface area, unprotected silanol groups and the methyl p-toluene sulfonate choline functionality on its surface. The mechanism of drug adsorption involves physical and chemical adsorptions with the presence of H-bonding and π-π stacking interactions