New Precursors towards the Hypergolic Synthesis of Inorganic Materials with Peculiar Morphologies

Author(s): Athanasios B Bourlinos

Hypergolic reactions have been recently introduced from our group as a radically new preparative tool in materials science, namely hypergolic materials synthesis, allowing the fast and spontaneous synthesis of several nanomaterials at ambient conditions in an energy-liberating manner. Although the majority of the examples given from our group in this context have been mainly referred to carbon, hypergolic materials synthesis can be, in principle, extended to the synthesis of inorganic materials as well. For instance, in previous works we have illustrated that metallocenes and metallocene dichlorides in combination with fuming nitric acid HNO3 are versatile organometallic reagents towards the hypergolic synthesis of a wide range of inorganic material. In our search for additionally new precursors towards the hypergolic synthesis of inorganic materials, here we take another step-forward to show the great potential of metal (IV) dimethylamides with fuming nitric acid HNO3 or of low melting point, hydrated transition metal salts (chlorides or nitrates) with sodium hydride NaH, in the synthesis of inorganic materials with peculiar morphologies through the corresponding hypergolic reactions. In particular, we show that titania TiO2 nanoparticles with twin structure can be derived by ignition of titanium (IV) dimethylamide with fuming nitric acid HNO3, whereas thin maghemite γ-Fe2O3 nanosheets by ignition of molten iron (III) chloride hexahydrate FeCl3•6H2O with sodium hydride NaH. The method can be equally applied to other metal (IV) dimethylamides or low melting point, hydrated transition metal salts with fuming nitric acid HNO3 or sodium hydride NaH, respectively, thus emphasizing the generality and simplicity of this new type of precursors in the hypergolic synthesis of inorganic materials.