Synthesis of amorphous vanadium oxide from metal alkoxide

Amorphous vanadium oxides were synthesized by the hydrolysis of tri-n-butoxy vanadyl, and three types of products, gel, green precipitates and red precipitates were obtained. These products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared absorption spectroscopy (IR), thermogravimetric-differential thermal analysis (TG-DTA) and chemical analysis. Properties of the products were correlated to the synthesis conditions, and the mechanisms of the formation of each product are proposed. (1) Gel has a network structure. It is formed when hydrolysis followed by condensation proceeds on three substitutional groups of tri-n-butoxy vanadile, (2) green precipitates are formed when the condensation reaction is inhibited. They are the aggregates of particles with small molecular weights and have short structure units with hydroxide groups at their ends, (3) red precipitates are caused by insufficient proceeding of hydrolysis. They have many alkoxy groups in their structure units and their molecular weights are between those of gels and green precipitates.