"Nanocomposites and nanomaterials"
Mechanochemical synthesis and characterization of ZnMoO4·0,8H2O, and ZnMoO4 nanostructures.
Diyuk N.V.1, Diyuk О.А.2, Zazhigalov V.O.2 Shcherban N.D.3
1 Taras Shevchenko National University of Kyiv, 60 Volodymyrska Street, Kyiv 01033, Ukraine 
2 Institute for Sorption and Problems of Endoecology of NAS of Ukraine, General Naumov Street, 13, Kyiv 03164, Ukraine E-mail: diyukhelen@ukr.net 
3 L.V. Pisarzhevsky Institute of Physical Chemistry, National Academy of Sciences of Ukraine,31 pr. Nauky, Kyiv 03028, Ukraine

ZnMoO4 is an industrial white pigment with anticorrosive and smoke-suppression properties. In addition, it has attracted more attention as a phosphor, catalyst for the partial oxidation of hydrocarbons, and anode material. At present, the traditional synthesis of ZnMoO4 is either energy-consuming or leads to water pollution. It is worth noting that water pollution and global warming are among the top ten major environmental problems. Therefore, the development of a synthesis procedure does not require high temperatures and does not lead to environmental pollution is a very urgent task. Our goal is to develop a low-temperature synthesis of ZnMoO4 without water pollution.
A mixture of ZnO and MoO3 with a molar ratio of 1:1 was treated mechanochemically on a Pulverisette-6 planetary ball mill in an aqueous medium with rotation of 500rpm for 10, 20, and 60 min. Synthesized samples were characterized by XRD, BET, SEM, TEM, FTIR, TPR-H2 and DTA. XRD data shows the formation of ZnMoO4·0.8H2O (JCPDS No. 00-025-1025) in all cases. SEM and TEM images of ZnMoO4·0.8H2O demonstrate the formation of flexible filament structures 20-100 nm wide and 200 µm long. These filament structures become entangled and form a secondary agglomerate web-like structure. Thermogravimetric measurements showed that ZnMoO4·0.8H2O has two forms of crystallized water: the first form desorbed up to 150°C, the second form desorbed in the temperature range of 150-280°C and at the same time ZnMoO4 (JCPDS No 00-035-0765) is formed. The TEM and SEM images of ZnMoO4 show that after the removal of the crystallization water, the flexible long structure was destroyed, and a structure of short needle-shaped particles was formed.
Mechanochemical treatment of a mixture of ZnO and MoO3 in water medium makes it possible to synthesize nanostructured zinc molybdate at room temperature, avoiding environmental pollution.