Examinando por Autor "Ortiz-Bustos, Josefa"

Mostrando 1 - 12 de 12

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, Gonzalo
Mortar 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 materials
Copper and sulphur co-doped titanium oxide nanoparticles with enhanced catalytic and photocatalytic properties
(RSC, 2020-07-29) Ortiz-Bustos, Josefa; Gómez-Ruiz, Santiago; Mazario, Jaime; Domine, Marcelo E.; del Hierro, Isabel; Pérez, Yolanda
Copper and sulphur co-doped titanium oxide nanoparticles have been prepared by the sol–gel method to develop versatile catalysts exhibiting enhanced catalytic and photocatalytic properties. Structural, morphological, chemical composition, and optical characterizations of the synthesized titanium oxide nanoparticles have been carried out in order to study the effect of incorporating copper and sulphur on the catalytic and photocatalytic activities of TiO2 nanoparticles. Optimal incorporation of copper and sulphur to the titanium dioxide nanoparticles promotes the photocatalytic degradation of ciprofloxacin in water under irradiation of UV or visible light. Complete degradation of ciprofloxacin was achieved after 120 min with the 0.4% Cu–0.5% S–TiO2 photocatalyst using UV and in 90 min applying visible light. Cu–S–TiO2 nanoparticles also exhibit high activity (94–98% conversion) and excellent recyclability (with no loss of activity after 14 runs) in selective oxidation of thioanisole using H2O2 as an oxidant.
Efficient visible-light-driven photocatalysis: simultaneous degradation of multiple pollutants with bismuth oxyhalide solid solutions
(Royal Society of Chemistry, 2024-06-24) Ortiz-Bustos, Josefa; Pérez del Pulgar, Helena; Gómez-Ruiz, Santiago; del Hierro, Isabel; Pérez, Yolanda
Visible-light-driven photocatalysis is considered as a sustainable and cost-effective method for water remediation. In aquatic environments, the coexistence of multiple contaminants, such as organic and inorganic compounds, poses a potential threat to both biological organisms and human health, complicating their removal. Despite the urgent need for the development of comprehensive solutions, the research on the concurrent and simultaneous removal of multiple pollutants remains limited primarily relies on photocatalysts based on heterojunctions. To address this issue, we have prepared BiOCl0.9I0.1 and BiOBr0.9I0.1 solid solutions, exhibiting well-tailored band gaps and energetics of the conduction and valence bands, using an easy chemical precipitation approach. These synthesized materials exhibited exceptional photocatalytic efficacy under visible light, effectively removing a complex mixture of contaminants, including ciprofloxacin (CIP), methylparaben (MP), and rhodamine B (RhB), from water. Particularly noteworthy was the outstanding performance of BiOCl0.9I0.1, which demonstrated a complete removal of RhB within 10 min, CIP within 40 min, and an 86% degradation of MP within 40 min. This superior performance can be attributed to the materials' exceptional optical and (photo)electrochemical properties. Furthermore, the synergistic or antagonistic effects coexisting contaminants, organic matter, and inorganic ions on the photodegradation process were also investigated. Additionally, the generation of reactive oxygen species (ROS), and the elucidation of the degradation pathways were examined providing valuable insights into the intricate interplay of environmental factors that may have an influence on the photocatalytic performance. Our study shows, therefore, the high potential of BiOCl0.9I0.1 and BiOBr0.9I0.1 as promising candidates for the simultaneous removal of diverse water pollutants, offering a robust and efficient approach towards advancing water purification technologies.
Exploring MOF-Nanoparticle Hybrids: Enhanced Performance in Contaminant Photodegradation and C–C Catalytic Coupling
(Springer Nature, 2024-06-15) García-Valdivia, Antonio A.; Ortiz-Bustos, Josefa; Méndez-Arriaga, José M.; Gómez-Ruiz, Santiago
This study reports the synthesis and characterization of seven novel hybrid materials integrating Metal–Organic Frameworks (MOFs) with diverse nanoparticles. Among these hybrids, four were anchored onto TiO2(F) nanoparticles and subjected to comprehensive characterization. Their catalytic efficacy was assessed against various contaminant models, revealing exceptional degradation capabilities, particularly in the breakdown of small molecules like phenol derivatives (e.g., 4-chlorophenol) compared to larger molecules such as methylene blue (MB) when exposed to UV light. Notably, these materials showcased superior degradation performance even surpassing that of pure TiO2(F) in its anatase phase. Conversely, our investigation extended to three newly developed nanomaterials derived from Pd nanoparticles as catalysts, which were evaluated for their catalytic activity in Suzuki–Miyaura and Sonogashira C–C coupling reactions. Remarkably, these Pd-based nanomaterials exhibited exceptional conversion and yield percentages at significantly low palladium concentrations, underscoring their high catalytic efficiency.
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, Yolanda
The 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, respectively
Novel templated mesoporous carbons as electrode for electrochemical capacitors with aqueous neutral electrolytes
(Elsevier, 2017-01-10) Ortiz-Bustos, Josefa; Real, Silvia Graciela; Cruz, Manuel; Santos-Peña, Jesús
In search for new electrodes for electrochemical capacitors, two template mesoporous carbons (TMC) are prepared with the replica method by using Plugged Hexagonal Templated Silica (PHTS) and Mesostructured Cellular Foam (MCF) as hard templates. No subsequent activation after synthesis is carried out in order to correlate textural and electrochemical properties in neutral sulfate electrolytes. TMC show interesting textural and conductive properties for capacitor electrode purposes: specific surface areas higher than 1000 m2 g−1, and low D/G bands ratio in the Raman spectra. Mesopore presence accounts for the fast formation of the double layer and the decrease of resistive properties which implies increased power properties referred to activated carbons. Symmetric carbon/carbon devices can provide energy densities 7–9 Wh kg−1 and maximal powers higher than 50 kW kg−1. These values compare well with 9 Wh kg−1 and 26 Wh kg−1 furnished by activated carbons. Nevertheless, such TMCs show two major issues for performing better than activated carbons in aqueous electrolyte capacitors. Firstly, they show surface carbon functionalities, narrowing the electrochemical window of the capacitor and decreasing the capacitor cycling life. Secondly, pore saturation is evidenced in these systems, unlike activated carbon, showing higher specific surface area and micropores content. Under prolonged cycling, our TMC electrode performance is poorer than that of activated carbon. However, mesoporosity positively affects the electrode response against increasing power. Beyond a power of 1.4 kW kg−1, only TMCs provide stable energy densities (>6.5 Wh kg−1), comparable or higher than those observed for activated carbons in corrosive electrolytes.
Photocatalytic oxidative desulfurization and degradation of organic pollutants under visible light using TiO2 nanoparticles modified with iron and sulphate ions
(Elsevier, 2022-03-01) Ortiz-Bustos, Josefa; del Hierro, Isabel; Pérez, Yolanda
The incorporation of iron and sulphate ions on TiO2 nanoparticles has been carried out in order to enhance catalytic performance in environmental remediation. The aim of this work is to design a multifunctional and visible-light active photocatalyst to remove pollutants from transportation fuels and water. The influence of doping with sulphur and iron on the physical, structural, optical, and electrochemical properties of TiO2 has been fully analyzed by a wide variety of techniques. Thus, the incorporation of a low amount of iron improves the photocatalytic performance, as in the case of 1.2%S-0.5%Fe–TiO2 photocatalyst, which shows the highest activity under visible light irradiation. The enhanced behaviour of the electron charge transfer of this photocatalyst has been confirmed by electrochemistry measurements including linear sweep voltammetry and electrochemical impedance spectroscopy. Also, the stability and recyclability of the best photocatalyst have been assessed
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 del
The 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.
Surface-functionalization of mesoporous SBA-15 silica materials for controlled release of methylprednisolone sodium hemisuccinate: Influence of functionality type and strategies of incorporation
(Elsevier, 2017-03-01) Ortiz-Bustos, Josefa; Martín, Antonio; Morales, Victoria; Sanz, Raúl; García-Muñoz, Rafael A.
Mesoporous SBA-15 silica materials functionalized with several organic moieties, that include different polarities and hydrophobicities, were investigated as matrices for controlled drug delivery. The functionalities were incorporated into SBA-15 using two methods: direct synthesis or co-condensation route and post-synthesis grafting. Methylprednisolone sodium hemisuccinate, a synthetic pharmaceutical compound used as anti-inflammatory and immunosuppressant, was loaded onto the pristine and functionalized mesoporous SBA-15 silica materials. The influence of the type of organic moieties as well as their incorporation method onto the inorganic silica framework has been evaluated. The results show that SBA-15 functionalized with aminopropyl trimethoxysilane groups has the largest capacity of drug adsorption, clearly higher than the provided by materials functionalized with other groups, independently of the synthesis route. Additionally, materials synthesized by the co-condensation approach show a lower degree of drug retention than the same material synthesized by grafting technique. This fact is attributed to the distinct localization of the functionality, more accessible in the case of the grafting procedure, and hence suggesting that stronger interactions among the SBA-15 functionalized surfaces and the model drug are established. To ascertain whether other organosilanes containing amino groups can provide more effective loading and controlled drug delivery, at neutral and acidic conditions (pH of 7.4 and 4.6, respectively), it was also investigated the incorporation by grafting of several amino organic moieties onto the SBA-15 silica materials. It was concluded that as the number of amino groups incorporated into SBA-15 material increased, not only the drug loading capacity was higher, but the functionalized silica material vehicles slowed down the drug delivery. Finally, it was confirmed that cell viability was largely unaffected by amino-functionalized mesoporous SBA-15 silica materials after 72 h of incubation time.
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 del
The 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
Tuning of type-I and type-II mechanisms for visible light degradation in tris(styryl)benzene-sensitized TiO2 nanoparticles
(Elsevier, 2021-01) Ortiz-Bustos, Josefa; del Hierro, Isabel; Sánchez-Ruiz, Antonio; García-Martínez, Joaquín C.; Pérez, Yolanda
The visible light activation of TiO2 have been carried out by sensitization method using robust and metal-free tris(styryl)benzene (TSB) compounds as efficient sensitizers, which can be easily prepared. TSB compounds decorated with three carboxylic acid (3COOH) or aldehyde (3CHO) groups have been tightly incorporated to the surface of TiO2 nanoparticles through different chemical linkage. The synthesized materials have been deeply characterized by different spectroscopic and analytical techniques to investigate the effect of TSB sensitizers in the photocatalytic properties of TiO2. Comparative and exhaustive optical studies have been performed in solution between TSB compunds and sensitized TiO2 nanoparticles, computational studies have been also carried to shed light on the sensitization process. The results reveal different mechanisms of sensitization (Type I and Type II) between the 3CHO and 3COOH compounds and TiO2 nanoparticles. Thus, the influence of electronic injection mechanism (direct or indirect) has been studied and mechanisms have been proposed for photodegradation of dye pollutants under UV and visible irradiation. TiO2 nanoparticles sensitized with 3COOH (TiO2-3COOH) exhibited the best visible photocatalytic activity with a removal efficiency around 98% for methylene blue in 30 min and methyl orange after 60 min.
Versatile titanium dioxide nanoparticles prepared by surface-grown polymerization of polyethylenimine for photodegradation and catalytic CeC bond forming reactions
(Elsevier, 2019-07-11) Ortiz-Bustos, Josefa; Fajardo, Mariano; del Hierro, Isabel; Pérez, Yolanda
Crystalline TiO2 anatase nanoparticles have been synthesized by a sol-gel procedure with a certain ratio of brookite phase due to low calcination temperature. TiO2 NPs have been successfully functionalized with hyperbranched polyethylenimine polymer (PEI) by the surface polymerization of aziridine or with N1-(3-trimethoxysilylpropyl)-diethylenetriamine (DT) by surface silanization to form catalyst with notable basic and photocatalytic properties. The TiO2 NPs have been characterized by X-ray diffraction (XRD), adsorption-desorption isotherms, fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance UV–vis spectroscopy (DRUV-vis), elemental analysis, thermogravimetric analysis, transmission electron microscopy (TEM), photoluminiscence spectroscopy (PL) and solid-state voltammetry. Functionalized TiO2 NPs have revealed to be efficient in the photodegradation of methylene blue in water and as basic heterogeneous catalysts carbon-carbon forming reactions as Knoevenagel condensation, multicomponent reactions and Biginelli reaction. PEI-TiO2 with mesoporous structure and narrow size pore distribution, fulfill the requirements imposed to an eco-friendly and cost-effective catalyst since it is easily synthesized and recyclable.