A hybrid electrochemical/chemical (E/C) synthesis of zinc oxide (ZnO) nanoparticles and films is described. The E/C procedure involves two steps:  Zinc metal was first electrochemically deposited at basal-plane oriented graphite electrode surfaces from dilute aqueous solutions; then this deposit was permitted to spontaneously oxidize and dehydrate at open circuit in the pH = 1.0 plating solution. Deposition was size-selective, and wurtzite phase ZnO nanocrystallites having mean diameters in the range from 15 to 100 Å were obtained using this approach. Relative standard deviations of the particle diameter for ZnO particle dispersions varied from 25 to 50%. Polycrystalline ZnO films of 100−400 Å in thickness were also obtained by depositing larger quantities of zinc metal in the first step of the synthesis. For ZnO particles (dia. < 80 Å), electron diffraction analysis revealed a preferred orientation for ZnO crystallites where the c-axis of the wurtzite unit cell was oriented perpendicular to the plane of the graphite surface, but X-ray powder diffraction data indicated that this orientational preference was lost when larger quantities of zinc were deposited and ZnO films were obtained. Luminescence spectra for the ZnO films prepared using this E/C method consisted of a single exciton band near 3.2 eV at room temperature with no deep trap state emission. At low temperatures (20 K), this exciton band split into a cleanly resolved and fully assignable phonon loss progression.

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Nanosized vanadium metal and iron oxide (Fe 2 O 3 ) powder with a purity of 99z% were mixed in the stoichiometric ratio. Powder specimens were fired in a tube furnace at 350-930uC for l h in Ar atmosphere. This is considered as a thermit reaction involving an oxidation reduction reaction of a metal reacting with a metallic oxide to form a more stable oxide and the corresponding metal. The reaction products were characterised using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, and the magnetic behaviour was measured using vibrating sample magnetometer. Also the catalytic decomposition of CO 2 was applied on the fired samples at 300-500uC. Reduction of iron oxide Fe 2 O 3 takes place at 930uC with the formation of the magnetite, wü stite, metallic iron and orthovanadate FeVO 4 phases in nanocrystalline size of y92 nm with characterised diluted magnetic properties. This fired products showed a catalytic activity towards CO 2 decomposition with the formation of single and multiwalled carbon nanotubes with average diameter 80-100 nm respectively.