WO3-decorated ZnO nanostructures for light-activated applications

In the present work, a two-step vapor-phase route was implemented for the tailored design of ZnO\u2013WO3 nanoheterostructures supported on fluorine-doped tin oxide (FTO) substrates. Under optimized conditions, the sequential use of chemical vapor deposition (CVD) and radio frequency (RF)-sputtering for the deposition of zinc and tungsten oxides respectively, resulted in the growth of calyx-like ZnO nanostructures uniformly decorated by a conformal dispersion of low-sized WO3 nanoparticles. The target materials were characterized by means of a multi-technique approach, with particular regard to their structural, compositional, morphological and optical properties. Finally, their photocatalytic performances were preliminarily tested in the abatement of NOX gases (NO and NO2). Due to the unique porous morphology of the ZnO nanodeposit and the high density of ZnO\u2013WO3 heterojunctions, WO3-decorated ZnO revealed appealing De-NOX characteristics in terms of both degradation efficiency and selectivity. Such features, along with the photoinduced superhydrophilicity and self-cleaning properties of the present nanomaterials, candidate them as promising functional platforms for applications in smart windows and building materials for environmental remediation

Spectroscopy and reactivity of transition metals. Módulos interactivos de aprendizaje for PC (e-learning) and mobile devices móviles (m-learning)

Se han desarrollado herramientas de aprendizaje autónomo en el campo de la Química, teniendo como temática la espectroscopia y complejos de los metales de transición. Los módulos de aprendizaje que se han desarrollado son de carácter auto-explicativo e interactivo para potenciar el aprendizaje autónomo del alumno, aunque tutelados por el profesor. También son de interés por su potencial aplicación en las modalidades de enseñanza virtual y semipresencial. Los módulos se han desarrollado para ser ejecutados tanto para ordenadores (e-Learning) como para dispositivos móviles (m-Learning), permitiendo trabajar no solo "on-line" sino también "off-line". Es decir, que las aplicaciones puedan ser descargadas e instaladas en los dispositivos fijos y/o móviles para su uso sin conexión a internet.We have developed some self-learning seminars in Chemistry. The main topic is the spectroscopy and complexes of transition metals. The learning modules developed are interactive and try to promote the autonomous learning of the student, although its use in this academic course will be tutored by the teacher. They are also of interest for their potential application in partial and fully on-line courses. All the modules can be downloaded and executed in both PC (e-Learning) and mobile devices (m-Learning), thus allowing to work not only "on-line" but also "off-line"

Photocatalytic NOx abatement by calcium aluminate cements modified with TiO2: improved NO2 conversion

Photocatalytic activity of TiO2 was studied in two types of Calcium Aluminate Cement (CAC) under two different curing regimes. The effect of the TiO2 addition on the setting time, consistency and mechanical properties of the CACs was evaluated. The abatement of gaseous pollutants (NOx) under UV irradiation was also assessed. These cementitious matrices were found to successfully retain NO2: more abundant presence of aluminates in white cement (w-CAC, iron-lean) helped to better adsorb NO2, thus improving the conversion performance of the catalyst resulting in a larger NOx removal under UV irradiation. As evidenced by XRD, SEM, EDAX and zeta potential analyses, the presence of ferrite in dark cement (d-CAC, iron-reach) induced a certain chemical interaction with TiO2. The experimental findings suggest the formation of new iron titanate phases, namely pseudobrookite. The reduced band-gap energy of these compounds compared with that of TiO2 accounts for the photocatalytic activity of these samples

Vapor-Phase Fabrication of \u3b2-Iron Oxide Nanopyramids for Lithium-Ion Battery Anodes

A vapor-phase route for the fabrication of beta-Fe2O3 nanomaterials on Ti substrates at 400-500 \ub0C is reported. For the first time, the beta polymorph is tested as anode for lithium batteries, exhibiting promising performances in terms of Li storage and rate capability

ESPECTROSCOPÍA Y REACTIVIDAD DE METALES DE TRANSICIÓN. MÓDULOS INTERACTIVOS DE APRENDIZAJE PARA PC (E-LEARNING) Y DISPOSITIVOS MÓVILES (M-LEARNING)

We have developed some self-learning seminars in Chemistry. The main topic is the spectroscopy and complexes of transition metals. The learning modules developed are interactive and try to promote the autonomous learning of the student, although its use in this academic course will be tutored by the teacher. They are also of interest for their potential application in partial and fully on-line courses. All the modules can be downloaded and executed in both PC (e-Learning) and mobile devices (m-Learning), thus allowing to work not only "on-line" but also "off-line".Se han desarrollado herramientas de aprendizaje autónomo en el campo de la Química, teniendo como temática la espectroscopia y complejos de los metales de transición. Los módulos de aprendizaje que se han desarrollado son de carácter auto-explicativo e interactivo para potenciar el aprendizaje autónomo del alumno, aunque tutelados por el profesor. También son de interés por su potencial aplicación en las modalidades de enseñanza virtual y semipresencial. Los módulos se han desarrollado para ser ejecutados tanto para ordenadores (e-Learning) como para dispositivos móviles (m-Learning), permitiendo trabajar no solo "on-line" sino también "off-line". Es decir, que las aplicaciones puedan ser descargadas e instaladas en los dispositivos fijos y/o móviles para su uso sin conexión a internet

Photocatalytic NOx abatement by calcium aluminate cements modified with TiO2: improved NO2 conversion

Photocatalytic activity of TiO2 was studied in two types of Calcium Aluminate Cement (CAC) under two different curing regimes. The effect of the TiO2 addition on the setting time, consistency and mechanical properties of the CACs was evaluated. The abatement of gaseous pollutants (NOx) under UV irradiation was also assessed. These cementitious matrices were found to successfully retain NO2: more abundant presence of aluminates in white cement (w-CAC, iron-lean) helped to better adsorb NO2, thus improving the conversion performance of the catalyst resulting in a larger NOx removal under UV irradiation. As evidenced by XRD, SEM, EDAX and zeta potential analyses, the presence of ferrite in dark cement (d-CAC, iron-reach) induced a certain chemical interaction with TiO2. The experimental findings suggest the formation of new iron titanate phases, namely pseudobrookite. The reduced band-gap energy of these compounds compared with that of TiO2 accounts for the photocatalytic activity of these samples

Study of NOx abatement by calcium alumniate cements modified by TiO2

Different percentages of TiO2 (1 to 10 wt.%) were incorporated into two different Calcium Aluminate Cements (iron rich – d-CAC – and iron lean – w-CAC–) which were cured under two curing conditions. The mild hydrothermal curing condition 2 was chosen so as to resemble the natural ageing of aluminate cements in which hydrated hexagonal phases are converted into more stable cubic ones. Fresh and hardened state properties were studied. NOx removal under UV illumination was assessed in TiO2-bearing mortar samples. NO conversion values were higher in w-CAC than in d-CAC. Retention of NO2 in w-CAC samples was also more successful than in d-CAC samples due to the presence of ferrite in the latter ones. The presence of ferrite in d-CAC was established by XRD, SEM and EDAX. The interaction of ferrite phases with TiO2 was monitored in both types of mortars and different behaviours were observed. In the d-CAC, the incorporation of TiO2 results in the appearance of two new iron containing phases: namely pseudobrookite and in a lesser extent ilmenite, at the expense of brownmillerite. These new phases yielded in an improve photocatalytic efficiency of d-CAC in the visible region of spectrum, as proved by Methyl Orange degradation tests