Use of Steel Industry Wastes for the Preparation of Self-Cleaning Mortars

An important problem, which must be solved, is the accumulation of industrial waste in landfills. Science has an obligation to transform this waste into new products and, if possible, with high added value. In this sense, we propose the valorization of the waste which is generated in the steel lamination process (HSL) through its conversion into a new material with photocatalytic activity which is suitable for use as an additive to obtain a self-cleaning construction material. The valorization of steel husk lamination waste is achieved through a grinding process, which allows the sample to be homogenized, in size, without altering its phase composition, and a thermal treatment that turns it into iron oxide, which acts as a photocatalyst. These residues, before and after treatment, were characterized by different techniques such as PXRD (Powder X-Ray Diffraction), TGA (Thermogravimetric Analysis), SBET (Specific surface area, Brunauer-Emmett-Teller), SEM (Scanning Electron Microscopy) and Diffuse reflectance (DR). MB and RhB tests show that this material is capable of self-cleaning, both of the material itself and when it is incorporated into a construction material (mortar). In addition, the NOx gas elimination test shows that it is also capable of acting on greenhouse gases such as NOx

Estudio del comportamiento electroquímico en baterías de litio de nanopartículas de Li2NiTiO4

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

ZnO on rice husk: a sustainable photocatalyst for urban air purification

A cost-effective and sustainable De-NOx photocatalyst is prepared usingzinc acetate and rice husk. ZnO@SiO2samples are obtained from the calcination of a homogenised precursor mixture at 600 C. ZnO nanoparticles (70 –180 nm) grow aggregated in spheres and well dispersed (40 –53 m2g-1surface area) covering the silicon skeleton. The corresponding band gap for ZnO@SiO2photocatalysts was estimated at3.1 –3.2 eV. When the samples are irradiated by sunlight in anitrogen oxide atmosphere the NO HNO2NO2NO3-photochemical oxidation takes place. In comparison to unsupported ZnO and TiO2-P25, ZnO@SiO2samples exhibit high NOXremoval values (70 %) and outstanding selectivity (> 90%), the latter related to the sensitivity of zinc oxide towards NO2gas. This new photocatalyst is easily recyclable and reusabl

Zn-Al layered double hydroxides as efficient photocatalysts for NOx abatement

In this study,we report that layered double hydroxides (LDH) exhibited high photocatalytic activitiesin degrading NOx gases for the first time. ZnAl-CO3LDHs with a 1.5 to 3.0 Zn/Al ratio were prepared by a coprecipitation method both with and without hydrothermal treatment.Syntheses were carried out with high and low metal concentrations, the latter being the most favorablein obtaining pure LDHs in the whole Zn/Al ratio range. The samples were characterized by different techniques suchas PXRD, FT-IR, ICP mass, TGA, SBET, SEM and Diffuse reflectance (DR). The LDH particlesgrew as well-defined hexagonal nanolayers, whosesize and crystallization dependedon the synthetic procedure and the Zn/Al ratio. Those samples with lower crystallinity exhibit the highest specific surface area values (> 50 m2·g-1). The ZnAl-CO3LDHs were UV light responsive with band–gap valuescloseto 3.5 eV. The LDH photocatalysts show a high performance towards the photochemical oxidation process of NO gas, withefficiencies of around 55 %. Remarkably, the ZnAl-CO3photocatalysts exhibit an impressive selectivity towards the deNOx process, avoiding the emission of the toxic NO2gas into the atmosphere. Interestingly,these promising deNOx results are repeated when working for a long irradiation period or with the highest concentration of NO in polluted atmospheres

Effect of boron addition on the electrochemical properties of LiFePO4

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Cr3+ substituted Zn-Al layered double hydroxides as UV–Vis light photocatalysts for NO gas removal from the urban environment

The ZnAl-CO3, ZnAlCr-CO3 and ZnCr-CO3 LDH samples were studied as De-NOx photocatalysts in this work. Samples without Cr and increasing the presence of Cr3+ in the LDH framework in the 0.06, 0.15 and 0.3 Cr/Zn ratio were prepared by co-precipitation method, all of them constituted by pure LDH phase. The increase of chromium content in the LDH framework leads to lower crystallinity and higher specific surface area in the samples. Moreover, the CrO6 octahedron centres expand the photo-activity from UV to Visible light and assist to decrease the recombination rate of the electrons and holes. The favourable textural, optical and electronic properties of Cr-containing LDH samples explain the good NO removal efficiency (55%) and outstanding selectivity (90%) found for the analysed De-NOx process