Low-temperature synthesis of nano-sized metal molybdate powders

Nanocrystalline metal molybdate [i.e., AMoO(4) where A = Ca(II), Co(II), Cu(II), Ni(Il), and Zn(II)] powders have been prepared from the complete evaporation of a polymer-based metal-complex precursor solution. The precursor solution was constituted of the metal ions that were in aqueous solution through complexation with ethylene diamine tetraacetic acid (EDTA) in the presence of diethanolamine (DEA), and a polymeric reagent, which was an aqueous solution mixture of sucrose and polyvinyl alcohol (PVA). Complete dehydration of the precursor solution generated a voluminous mesoporous carbon-rich precursor mass, heat treatment (at temperatures less than or equal to 500 degreesC) of which resulted in the respective metal molybdate phase. The average diameter of the particles from transmission electron microscopy and X-ray diffraction studies ranged between 15 and 40 nm. (C) 2001 Elsevier Science B.V. All rights reserved.