Nanosized metal oxides: synthesis, structure, physico-chemical and electrochemical properties, applications.
It is known that substances with crystal size less than 100 nm possess some valuable properties which are not known for the substances in bulk or macrocrystal state. In particular, nanosized metal oxides become electrochemically active, which permit to use them in energy storage systems.
The conditions for the reactions of oxidation of metals (titanium, tin, tantalum) and their compounds were determined for the synthesis of the nanosized oxides.
It was established that the composition and properties of the product can be regulated by means of the change in the “basicity” of the reaction media.
The samples of potassium metatantalate powder with crystal sizes about 80-90 nm were obtained from the nitrate melt for the first time. Such material can be used in the modern optoelectronics.
It was shown for the first time that, depending on the synthesis conditions, the TiO2 oxide can be obtained either in form of common nanocrystals of 30-50 nm or in form of one-dimensional (1D) nanowires with 10-20 nm diameter and 200-300 nm long.
Electrochemically active (with regard to the reaction of the electrochemical lithium intercalation) nanomaterials were obtained based on the tin and titanium oxide. These materials can be used as the electrode materials in new generation of safer lithium-ion batteries.
It was shown that creation of nanosize centres on the surface of carbon materials (graphite, nanowires) by means of grafting the 2d-metal complex compounds permits to improve significantly the electrochemical properties of such materials in the reactions of electrochemical insertion of lithium and evolution of hydrogen.