Nanocomposites and nanomaterials
Synthesis of ZnCr2O4 nanoparticles with certain size and morphology
Mykhailovych V.V.1, Kanak A.I.2, Starchuk M. P.2, Fochuk P.M.2
1 Department of Solid State Physics, Yuriy Fedkovych Chernivtsi National University, Kotsubinsky 2, Chernivtsi-58012, Ukraine
E-mail: mykhailovych.v@gmail.com
2 Department of General Chemistry and Material Science, Yuriy Fedkovych Chernivtsi National University, Kotsubinsky 2, Chernivtsi- 58012, Ukraine.

Spinel-type nanoparticles (NPs) [1] are a promising material for use in various fields including medicine, electronics, chemical engineering, industry, etc. In particular zinc chromite is perspective nanomaterial for catalysts and photocatalysts, humidity sensors, toxic gases detecting sensors, etc. 
Application of the ZnCr2O4 NPs in various industries requires certain shape, size and surface of the corresponding nanoparticles. Therefore these parameters change the catalytic, magnetic, adsorption and other properties. Several works including [2] ware devoted to investigate the morphology of zinc chromite NPs but actually any research provides the answer about the controlled formation of ZnCr2O4 nanoparticles with a predictable size and shape. 
The current research is focused on controlled synthesis of ZnCr2O4 NPs with a predetermined size and shape. The sol-gel auto-combustion method was used as a synthesis route [3]. The zinc acetate and chromium nitrate with tartaric acid as a combustion agent were used as a started materials. The post auto-combustion treatments within 5 hours were carried out at 500 °C, 600 °C, 700 °C, 800 °C and 900 °C respectively. It provides the formation of spherical NPs with 5 nm in size at 500 °C and octahedral NPs with 300 nm in size at 900 °C. During the research was found that shapes of NPs are change from spherical to octahedral through the cubic shape.  The big part of obtained NPs during the thermal treatment at 700 °C and 800 °C possessed a cubic shape. 

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2.	Mancic L., Marinkovic Z., Vulic P., Moral C., Milosevic O. Morphology, structure and nonstoichiometry of ZnCr2O4 nanophased powder. J Sensors.-2003.-10.- P. 415–423.
3.	Rida K., Benabbas A., Bouremmad F., Pen M., Martınez-Arias A. Influence of the synthesis method on structural properties and catalytic activity for oxidation of CO and C3H6 of pirochromite MgCr2O4 // Applied Catalysis A: General.-2010.-375.-P. 101–106.