Polycrystalline bismuth vanadate, BiVO4, was synthesized by metallo-organic decomposition (MOD), starting from bismuth 2-ethyl-hexanoate and vanadium (IV) oxy-acetylacetonate solutions in an organic solvent. The pyrolysis of the precursors at 500degreesC lead to single-phase samples, with particle sizes ranging from 0.65 to 1.40 mum, depending upon the heating time. The activation energies for the thermal decomposition of the precursors were estimated as 100.0 kJ/mol and 90.5 kJ/mol for bismuth and vanadium precursors, respectively. The method allows for the synthesis of powdered polycrystalline and/or thin film samples and may provide a route to doped/substituted compounds with minimal changes in the experimental procedures. (C) 2002 Kluwer Academic Publishers.371019231927