Disordered Mesoporous Zirconium (Hydr)oxides for Decomposition of Dimethyl Chlorophosphate.

A facile method for the formation of mesoporosity within nonporous zirconium hydr(oxides) (ZrO2/Zr(OH)4) is presented and their detoxifying capabilities against dimethyl chlorophosphate (DMCP) are investigated. Nanoaggregates of ZrO2/Zr(OH)4 appear to be deposited on larger thin flakes of the same material. H2O2 is used to induce surface oxygen vacancies of synthesized ZrO2/Zr(OH)4 and, as a consequence, mesopores with an average diameter of 3.1 nm were formed. A surface area of H2O2-treated ZrO2/Zr(OH)4 was increased by an order of magnitude and shows enhanced reactivity toward DMCP. DRIFTS spectroscopy is employed to assess the reactivity differences between the H2O2-treated and untreated ZrO2/Zr(OH)4. Peaks at 1175 and 1144 cm-1 indicate the presence of asymmetric stretching of the O-P-O moiety within dimethyl phosphonate (DMHP), a decomposition product from DMCP, and a zirconium-bound methoxy group, respectively. It is suggested that the decomposition of DMCP proceeds through the consumption of bridged hydroxyl groups (b-OH) for both the untreated and H2O2-treated samples, as well as an additional hydrolytic decomposition pathway for the H2O2-treated sample.

In Situ Growth and Characterization of Metal Oxide Nanoparticles within Polyelectrolyte Membranes.

This study describes a novel approach for the in situ synthesis of metal oxide-polyelectrolyte nanocomposites formed via impregnation of hydrated polyelectrolyte films with binary water/alcohol solutions of metal salts and consecutive reactions that convert metal cations into oxide nanoparticles embedded within the polymer matrix. The method is demonstrated drawing on the example of Nafion membranes and a variety of metal oxides with an emphasis placed on zinc oxide. The in situ formation of nanoparticles is controlled by changing the solvent composition and conditions of synthesis that for the first time allows one to tailor not only the size, but also the nanoparticle shape, giving a preference to growth of a particular crystal facet. The high-resolution TEM, SEM/EDX, UV-vis and XRD studies confirmed the homogeneous distribution of crystalline nanoparticles of circa 4 nm and their aggregates of 10-20 nm. The produced nanocomposite films are flexible, mechanically robust and have a potential to be employed in sensing, optoelectronics and catalysis.