Nanocomposites and nanomaterials

Synthesis and structure of SiO2 and Al2O3-supported Ni and Co- nanooxide composites 
Goncharuk O.V.1, Dyachenko А.G.2, Ischenko O.V.2, Pakhlov E.M.1,  Sulym I.Ya.1, Andriyko L.S. 1, Marynin A.I. 3, Pasichnyi V.M.3
1 Chuiko Institute of Surface Chemistry of the NAS of Ukraine, General Naumov Str. 17, Kyiv 03164, Ukraine. E-mail: iscgoncharuk@meta.ua 
2 Taras Shevchenko National University of Kyiv, 64/13 Volodymyrs’ka str., 01033 Kyiv, Ukraine
3National University of Food Technology, 68 Volodymyrska Str., 01033 Kyiv, Ukraine

In the last decade, much attention is paying to the development of novel  nanocomposites based on highly dispersed mixed oxide systems to expand their functional properties as adsorbents, catalysts, catalyst carriers or fillers by varying the porous structure, specific surface area, formation of various active surface centers, in particular with Bronsted and Lewis acidity. One of the effective ways to synthesize mixed oxide composites is the deposition of the second phase on a highly dispersed matrix of non-porous oxide, as which in this work were used the fumed oxides with non-porous structure, namely nanosilica SiO2 (SBET=79.7 m2/g), alumina Al2O3 (SBET=72.0 m2/g), alumosilica SiO2/Al2O3 (SA96, SBET=65.4 m2/g) and alumotitanosilica SiO2/Al2O3/TiO2 (AST1, SBET=91.4 m2/g) [1]. The advantage of this method is the ability to adjust the structure of the composite by influencing the interaction of the surface active centers of the nanocarrier on the structure formation of the guest oxide phase. As the guest oxide phase, NiO/FexOy and Co3O4/FexOy oxides were deposited by pre-solvate-stimulated adsorption modification of the surface of fumed nanocarriers with Ni and Co nitric acid salts and Fe formate and subsequent heat treatment up to 600 °C to form the structure of the NiO/FexOy and and Co3O4/FexOy oxide phases. Studies of the structure of the synthesized composites by SEM and DLS methods showed a tendency to form dense aggregates with a size from 100 nm to 10 μm due to modifying the nanocarrier with the guest oxide phase while maintaining the nanosize of the primary particles that form them. The surface content of Ni and Co was 12.4-15.0 % wt. and Fe was 3.3-4.1 % wt. according to SEM EDX data.
1.	Gun’ko V.M., Turov V.V., Zarko V.I., Goncharuk O.V., Pakhlov E.M., Skubiszewska-Zięba J., Blitz J.P./ Interfacial phenomena at a surface of individual and complex fumed nanooxides // Advances in Colloid and Interface Science. -2016.- V.235. P.108-189.