The aldol condensation of acetaldehyde and heptanal on NiMg(Al)O mixed oxides obtained from LDH precursors

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Doping titanium dioxide with palladiun for enhancing the photocatalytic decontamination and mineralization of a refractory water pollutant

International audienceThe photocatalytic performance of a commercial TiO2 doped by incipient wet impregnation with palladium (sample named TiO2-Pd), was evaluated in the heterogeneous degradation process using as test molecule the clofibric acid (CA), a metabolism product of a drug used as blood lipid regulator. The catalyst was characterised by XRD, SEM and UV-VIS reflectance spectroscopy. The photocatalytic potential of this new catalyst was evaluated at laboratory scale under UV-A irradiation conditions. The influence of a few key parameters was studied in order to optimize the process conditions. The results shown that TiO2-Pd can completely remove the target pollutant under the optimal conditions (0.2 g/L catalyst, 5 mg/L CA, 6.2 mW/cm2 irradiation flux). Moreover, the CA mineralization was evaluated by TOC and a 65% mineralization yield was obtained, confirming the good photocatalytic activity of TiO2-Pd. © 2020 SYSCOM 18 S.R.L.. All rights reserved

Photocatalytic treatment of colored wastewater from medical laboratories: photodegradation of Nuclear Fast Red

The degradation and organic content reduction of Nuclear Fast Red (NFR, a counterstain reagent widely used in biochemical and biomedical laboratories) in aqueous solutions has been studied by heterogeneous photocatalytic oxidation under artificial irradiation. For the heterogeneous processes, the performance of different commercial titanium oxides on the degradation and the organic content reduction (DOC) of the wastewater was examined. The decomposition of the NFR follows quite well a pseudo-first kinetic order in the whole pH range, in line with the Langmuir–Hinshelwood model. The effects of catalyst concentration, of the initial solution pH and of H2O2 concentration upon the reaction rate, were also investigated. NFR degradation was accompanied by the formation of ammonium, nitrate, and sulfate ions, as they have been detected as mineralization products in the liquid phase. © 2015 Balaban Desalination Publications. All rights reserved

Catalytic properties of oxide nanoparticles applied in gas sensors

A series of gas sensing layers based on indium oxide doped with gold were prepared by using the aerosol technology for deposition as the active contact layer in a metal oxide semiconductor capacitive device. The interaction between the measured species and the insulator surface was quantified as the voltage changes at a constant capacitance of the device. The sensor properties were investigated in the presence of H2, CO, NH3, NO, NO2 and C3H6 at temperatures between 100–400 °C. Significant differences in the morphology of the layer and its sensitivity were noted for different preparation methods and different gas environments