Potential biomedical application of a new MOF based on a derived PET: synthesis and characterization

Sintesis y caracterizacion de MOFS con aplicacione sbiomedica

Desarrollo de fotocatalizadores basados en TiO2 en forma de película delgada para la degradación de moléculas orgánicas en solución acuosa

En este volumen ademas del capitulo, participo como editora invitadaTiO2 is used in a wide variety of applications, including photocatalysis in the environmental area for surface self-cleaning as well as air and water purification. In order to develop new materials with better photocatalytic response, it has been proposed the modification of TiO2 following different strategies. In this work, the basics of photocatalysis are summarized discussing the advantages of using photocatalysts in thin film form. The results of the preparation and characterization of zinc-modified TiO2 thin films using a novel synthesis route are presented; these indicate that depending on the Zn load incorporated into the film mixtures of TiO2 with Zn titanates are formed. The obtained results in the photocatalytic evaluation of the films in the degradation of the malachite green dye are shown, it was found that the films containing Zn have a better response practically doubling the degradation degree obtained with the sample without Zn. KEYWORDS: photocatalysis, TiO2, thin film, malachite green

Advanced Oxidation Processes II: Removal of Pharmaceuticals by Photocatalysis

In this chapter, basic concepts of advanced oxidation processes (AOP) are cited, such as photolysis, photocatalysis, and semiconductors used as photocatalysts. This is important since the wastewater pollution with drugs, coming from domestic use, hospitals, and industry is not only an environmental problem but social too. Pharmaceutical case study is shown to exemplify the photocatalytic degradation of different drugs contained in wastewater taken directly from some currents in the pharmaceutical industry, such as diclofenac, acetaminophen, naproxen, and ibuprofen, using modified TiO2 catalysts with different tin contents.CONACy

Advanced Oxidation Processes: Ozonation and Fenton Processes Applied to the Removal of Pharmaceuticals

This chapter aims to present the fundamentals, important variables, and pharmaceuticals removed by ozonation and Fenton, which are only two of the current existing advanced oxidation processes. Some toxicological information regarding pharmaceuticals oxidized by ozonation is also included. Some strategies to improve such processes, like adding a catalyst, light, or electrical current, are also analyzed. Thus, this chapter intends to present general but fundamental aspects of the aforementioned processes

Photocatalytic Activity under Simulated Sunlight of Bi-Modified TiO2 Thin Films Obtained by Sol Gel

The synthesis of Bi-modified TiO2 thin films, with different Bi contents, is reported. The obtained materials were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), X-ray diffraction (XRD), photoluminescence (PL), and diffuse reflectance spectroscopy (DRS), in order to obtain information on their chemical composition, vibrational features, and optical properties, respectively. Compositional characterization reveals that the bismuth content can be varied in an easy way from 0.5 to 25.4 at. %. Raman results show that the starting material corresponds to the anatase phase of crystalline TiO2, and Bi addition promotes the formation of bismuth titanates, Bi2Ti2O7 at Bi contents of 10.4 at. % and the Bi4Ti3O12 at Bi contents of 21.5 and 25.4 at. %. Optical measurements reveal that the band gap narrows from 3.3 eV to values as low as 2.7 eV. The photocatalytic activity was tested in the degradation reaction of the Malachite Green carbinol base dye (MG) as a model molecule under simulated sunlight, where the most relevant result is that photocatalytic formulations containing bismuth showed higher catalytic activity than pure TiO2. The higher photocatalytic activity of MG degradation of 67% reached by the photocatalytic formulation of 21.5 at. % of bismuth is attributed to the presence of the crystalline phase perovskite-type bismuth titanate, Bi4Ti3O12.SIEA UAEM 4488 CHT project, CONACyT CB-168827 and CB-24099

Relevant changes in the properties of Co(Ni)Mo/Al2O3 HDS catalysts modified by small amounts of SiO2

The changes in hydrodesulfurization activity, selectivity, dispersion, sulfidation, and extent of promotion of Co(Ni)Mo catalysts were investigated when the alumina support surface is modified by grafting 4 wt% silica. Adding SiO2 eliminates the most reactive hydroxyl groups on the alumina surface (IR band at 3775 cm 1) decreasing the possibility of generating tetrahedral Mo species difficult to sulfide in favor of octahedral ones capable of contributing to the sulfided active phase. The catalysts were evaluated in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. Incorporating SiO2 to alumina increases the hydrogenation rate constant and therefore the global hydrodesulfurization rate of 4,6-dimethyldibenzothiophene and enhances the promotion of Mo by Co (or Ni). The global sulfidation of Ni is not affected by the addition of silica but the sulfidation of cobalt is significantly improved. The extent of promotion of the NiMo/Al2O3 and NiMo/SiO2/ Al2O3 catalysts was greater than the one achieved in their Co-promoted counterpartsCB-168827, beca posdoctoral otorgada por CONACyT al Dr. Adolfo Romero Galarza from DGAPA-UNAM, project PAPIIT-IN-113015. We thank Mariela Bravo-Sanchez (Universidad de Guadalajara) for her discussion about the XPS results, Ivan Puente for the TEM work, and Alberto Herrera-Gómez (CINVESTAV-Unidad Querétaro, Mexico) for providing computer program AANALYZER version 1.2

Synthesis and characterization of silver vanadates thin films for photocatalytic applications

Silver vanadates thin films were deposited by a hybrid deposition system combining laser ablation and thermal evaporation. A high purity vanadium target was ablated using the third harmonic of a Nd:YAG laser whereas high purity silver pellets were evaporated. The as-deposited thin films were subjected to thermal treatments at 400 °C to obtain crystalline films. For films without Ag amorphous V2O5 thin films were deposited and as the Ag is incorporated in the material different silver vanadates were obtained. The effect of the silver load on the composition, structure, optical properties, surface morphology and photocatalytic response of the deposited films was studied. The film composition, determined by X-ray photoelectron spectroscopy, reveals Ag contents from 5.5 to 18.9 at.%. The crystalline phases formed were identified by micro-Raman Spectroscopy; the results indicate the formation of three silver vanadates depending on the silver content. The morphology was observed using scanning electron microscopy, the filmś surface changes from a smooth surface to belts covering the surface and finally Ag nanoparticles are observed at the higher Ag contens. Optical properties determined from UV–vis reveal the presence of the surface plasmon signal in films containing silver. The films were tested in the photocatalytic degradation of Malachite Green dye reaching maximum degradations degrees close to 53% under solar irradiation. Reactive species trapping experiments suggest that O2 − produced by the O2 reduction via the photogenerated electrons drives the photodegradation mechanismCB-168827 CB-240998 F. Gonzalez-Zavala thanks to CONACyT for the PhD and Beca Mixta grants, and also to the SIEA-UAEM for the beca movilidad para estudios avanzados 2016. E. Rodríguez-Castellón thanks to project CTQ2015-68951-C3-3-R of Ministerio de Economía y Competitividad (Spain) and FEDER funds

Two-dimensional carbon nanostructures obtained by laser ablation in liquid: effect of an ultrasonic field

en este articulo se detallan procedimientos de síntesis de materiales novedosos obtenidos por ablación láserThe ablation of a carbon target immersed in deionized water, in absence and in presence of ultrasonic waves is reported, and the differences investigated. The obtained nanostructures are characterized by transmission electron microscopy, Raman spectroscopy and photoluminescence. Transmission electron images reveal that the produced carbon nanostructures, with and without ultrasonic excitation, are graphene-like sheets with improved quality in the first case. Samples prepared with ultrasounds show graphene layers with large sizes (several microns) and regular shapes, whereas the samples prepared without ultrasounds show smaller sizes and irregular shapes; additionally, some dispersed quasi-spherical nanoparticles are observed in the samples prepared without ultrasound. Photoluminescence measurements of the obtained nanostructures reveal emission in the blue spectral region.conacy

Temas selectos en ciencia de materiales i (pdf)

Se presentan una selección de 12 capítulos de diferentes investigadores , los temas de esta obra se encuentran relacionados con polímeros y sus compuestos, nanoestructuras metálicas y óxidos metálicos.El presente libro de investigación tiene como objetivo difundir a la comunidad estudiantil de nivel licenciatura y posgrado, principalmente, algunos temas de actualidad en el campo de Ciencia de Materiales, para motivarla e interesarla en esa área tan importante. Se espera también que el libro sea de utilidad para estudiantes de posgrado en Ciencias e Ingeniería de Materiales o áreas afines

Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM

Se describe brevemente el origen del Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM (CCIQS). Se presentan principalmente las actividades científicas que se desarrollan en este centro relacionadas con la nanociencia y la nanotecnología (NyN), y a los investigadores responsables de las mismas. Además, se relata de manera sucinta la importancia de la formación de recursos humanos a través de los programas de licenciatura y posgrado de la Facultad de Química de la UAEM