Bimetallic Au-Pd and Ag-Pd Clusters Synthesised by γ or Electron Beam Radiolysis and Study of the Reactivity/Structure Relationships in the Selective Hydrogenation of Buta-1,3-Diene — Ag-Pd and Au-Pd (alloyed or core-shell) catalysts were synthesised by radiolytic reduction (gamma rays or electron beam). Selective hydrogenation of buta-1,3-diene was performed with these different nanoparticles deposited on alumina in order to investigate composition and structure effects on catalytic performances. Au-Pd and Ag-Pd nanoparticles exhibit very different catalytic behaviours: whereas only hydrogenation activity is modified on Au-Pd systems without any change in selectivity toward butenes formation, important variations in selectivity into butenes are observed for Ag-Pd nanoparticles deposited on alumina support.

CeO₂/ZnO-based photocatalytic materials were synthesized by the sol-gel method in order to establish heterojunctions that increase the degradation efficiency of some types of antibiotics by preventing the recombination of electron–hole pairs. The synthesized materials were analysed by XRD, SEM, EDAX, FTIR, and UV-Vis. After several tests, the optimal concentration of the catalyst was determined to be 0.05 g‧L⁻¹ and 0.025 g‧L⁻¹ for chlortetracycline and 0.05 g‧L⁻¹ for ceftriaxone. CeO₂/ZnO assemblies showed much better degradation efficiency compared to ZnO or CeO₂ tested individually. Sample S3 shows good photocatalytic properties for the elimination of ceftriaxone and tetracycline both from single solutions and from the binary solution. This work provides a different perspective to identify other powerful and inexpensive photocatalysts for wastewater treatment.

TiO₂ nanoparticles synthesized by the sol-gel method and doped with Ag were characterized by SEM, EDAX, FTIR, BET, XRD and TEM, then tested in the photocatalytic degradation of methylene blue (MB) under UV irradiation. The experimental results indicate that the average size of the raw particles was 10 nm, and their size was increased by calcination. The photocatalytic degradation of MB on nanostructured TiO₂-Ag shows a high degradation efficiency upon the addition of a photosensitizer. A parametric study of the process was performed and has revealed the optimal value of the photocatalyst dose (0.3 g L⁻¹) at a MB concentration of 4 ppm. Afterwards, the effect of acetone as a photosensitizer was studied. A MB degradation mechanism was proposed to explain the synergy between the TiO₂ and the silver nanoparticles in the degradation performance. Under the optimal experimental conditions, at photosensitizer doses of 0.1 and 0.2%, yields of 92.38% and 97.25% MB degradation were achieved, respectively. Kinetic models showed that, at 0.1% acetone concentration, the data fit the pseudo-first-order model, while at 0.2% acetone, the photodegradation mechanism fits a second-order model. The values of the apparent rate constants indicate that the reaction rate increased between 24 and 40 times in the presence of acetone on TiO₂ and TiO₂-Ag. The addition of acetone modified the photodegradation mechanism and the Ag-doped samples became more active. The results of recycling tests using calcined TiO2-Ag material clearly show that the material was highly photocatalytically stable for the MB degradation. According to experimental results, the dye degradation decreased from 97.25% to 92.39% after four consecutive cycles. This simple approach could be applied for the advanced cleaning of wastewater contaminated with dyes, in the perspective of its reuse.

In this paper the rheological behavior of three cold creams obtained in laboratory have been made, such as: simple cold cream, one cream with cinnamon extract and one cream with thuja extract. All three creams have a pseudo-plastic time-dependent rheological behavior, also exhibiting a velvety feeling and being easily applied on skin. By adding the alcoholic extracts of cinnamon and thuja, the creams became more fluid and soft and could be applied better.