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The design of new specific photocatalysts to achieve excellent photocatalytic performances in the photodegradation of organic pollutants, specially the nonbiodegraded ones, is of a crucial importance nowadays to clean the contaminated water resources aiming to solve the problem of shortage in clean water. In this work, a cobalt supported over hexagonal mesoporous silica (9%Co/HMS) catalyst was synthesized and applied in the removal of Metronidazole in aqueous solutions by photodegradation under sunlight. An unexpected excellent photocatalytic performance was obtained (97% of MNZ removal in sunny days vs. 74% in cloudy days). This excellent performance results from the creation of a semiconductor–insulator heterojunction between Co3O4 and the carrier HMS. Even more interesting, the removal efficiency was kept up four cycles. Therefore, this study may provide a new opportunity for the future development of high-performance heterogeneous catalysts based on mesoporous silica in aquatic environmental pollution control in either sunny or cloudy weather. [ABSTRACT FROM AUTHOR]

Pyrophyllite is the least studied natural clay in terms of its potential in biomedical applications, although there are many deposits of this aluminosilicate around the world. Genotoxicity study was performed in vitro for this mineral. Subsequently, Wister rats were exposed to the pyrophyllite micronized to below 100 µm. After the exposure period, histology of the lung, liver, kidney and gastric tissues were performed, followed by the stereological and hematological analysis. The physicochemical analyses revealed typical XRD characteristics of pyrophyllite clay with particle-size distribution ranging 50 nm–100 μm with stable mineral composition and unique buffering property to pH around 8. The results showed that there were no cytotoxic effects on to THP-1 cells, or genotoxicity of pyrophyllite measured by the Comet assay. In vivo studies are accompanied by the thorough physicochemical characterization of the micronized pyrophyllite. Histology of the lung tissue proved presence of an inflammatory reaction. On the other hand, gastric tissue has shown the selective accumulation of nanoparticles in enterocytes of the stomach only, as supported by ultrastructural analysis. Liver and kidney tissues have shown tolerability for pyrophyllite particles. The results give directions for further comprehensive studies of potential biomedical applications of the pyrophyllite. [ABSTRACT FROM AUTHOR]

Quaternary ammonium salts of metal derivatives of polyoxometalates [XW11O39M(H2O)]n− (X = P, Si; M = Cr, Mn, Co, Ni, Zn) were successfully tested instead of quaternary ammonium halides as catalysts in the cycloaddition of CO2 to styrene oxide. Remarkably, they gave very satisfactory yields of styrene carbonate at moderate temperature (80 °C). [ABSTRACT FROM AUTHOR]

This paper focuses on the hydrogenolysis of 2‐phenoxy‐1‐phenylethanone, modelling a pre‐oxidized form of lignin using five catalysts of similar metal content, prepared by impregnation of Ni(II), Rh(III) and both metals onto Aerosil‐380 in the presence of NH3, followed by a reduction step. The materials were characterized in the dried as‐synthesized state and after consecutive reductive and oxidative treatments, showing the great dispersion of the metal (oxide nanoparticles with sizes<2 nm). Working with 1 mol % of the reduced metal (500 °C) per substrate at 180 °C with isopropanol as H‐donor, the most active catalyst, but also the least selective towards phenol, was initially found to be the Ni‐based one. Under similar conditions, the lower capacity of the Rh‐based catalyst to induce H transfer from isopropanol favoured phenol formation but resulted in much slower C−OAr cleavage. Despite a very high dispersion of the two metals in the bimetallic catalysts, no synergy was found, suggesting that Ni would be segregated at the surface. Finally, the best phenol productivity could be reached by reducing the Ni‐based catalyst at 650 °C, which led to a more efficient cleavage of C−OAr bonds. In this way, it was possible to produce 8 times more phenol per hour. [ABSTRACT FROM AUTHOR]