Nanocomposites and nanomaterials. 

Characterization of nanosize ZnMoO4 synthesized by mechanochemical and ultrasonic methods 
N.V. Diyuk1, V.A. Zazhigalov2, O.V. Sachuk2, M.M.Tsyba2
1Taras Shevchenko National University of Kyiv 60 Volodymyrska Street, Kyiv 01033, Ukraine, nadia146nadia@gmail.com
2 Institute for Sorption and Problems of Endoecology of NAS of Ukraine, General Naumov Street, 13, Kyiv 03164, Ukraine, slena951@ukr.net

ZnO/MoO3 system is well known for applications in bolometers, scintillation detectors, humidity sensors, microwave dielectric devices, battery electrodes and catalysis. Currently, ZnMoO4 synthesis requires high energies or large amounts of water [1].
The synthesis of ZnMoO4 with using powders of oxides MoO3 and ZnO (molar ratio 1:1) as raw materials was carried out by three ways:
i) The mechanochemical method of synthesis (MCh) was carried out in the planetary ball mill Pulverisette-6 (Fritsch) in air during 8 h; ii) The ultrasonic methods synthesis (US) was carried out in dispersant UZDN-2T in aqueous solutions during 1 h and iii) The conventional solid-state (SS) reaction at 900°C during 6 h. Initial and synthesized samples were characterized by adsorption of N2, FT-IR, EPR, XRD, SEM with EDS and TEM methods.
The XRD data show that the US and SS syntheses lead to formation α- ZnMoO4 while MCh synthesis accompanied by formation of β-ZnMoO4. SEM microphotographs demonstrate homogeneous morphology of surface and results of EDS analysis show equivalent smooth element content. TEM analyses demonstrate formation nanosized needle-like crystals for α-ZnMoO4 synthesized by US method and rod-like crystals for β-ZnMoO4 which is obtained by MCh treatment. H2 – TPR of initial oxides and zinc molybdates ZnMoO4 which are obtained by above mentioned methods show the significant differences on TG and DTG curves. The catalytic study of the samples synthesized by MCh and US demonstrated a high activity and selectivity to acetaldehyde at low temperature in bio-ethanol oxidation to acetaldehyde reaction. The most effective catalyst is β-ZnMoO4, which demonstrates the acetaldehyde yield of 96% at 205°C. 
1.	Y. Keereeta , T. Thongtem, S. Thongtem Effect of medium solvent ratios on morphologies and optical properties of a-ZnMoO4, b-ZnMoO4 and ZnMoO4·0.8H2O crystals synthesized by microwave-hydrothermal / solvothermal method // Superlattices and Microstructures – 2014. - 69. - P. 253–264.