Room temperature synthesis of K2Mo3O10x3H2O nanowires in minutes.

Polyoxometalates have been widely used in the fields of catalysis, analytical chemistry, biochemistry, medicine and synthesis of novel organic-inorganic materials. It is difficult to synthesize pure polymolybdate products from a solution because several kinds of molybdenum-based anions may coexist. As a result, varied acidification methods are commonly used for solution synthesis of polymolybdates. In this paper we report an approach for the synthesis of [001]-oriented K(2)Mo(3)O(10)x3H(2)O nanowires from an aqueous solution of (NH(4))(6)Mo(7)O(24)x4H(2)O and KCl at low temperatures. The reaction occurs even at temperatures as low as 0 degrees C, and at 30-90 degrees C the whole procedure needs only a few minutes. Without any additional acidification treatments, the pH value of the solution is maintained in a narrow range of +/- 0.1 between 4.9 and 5.5 during the whole synthesis procedure. The starting pH depends on the reaction temperature. Crystalline structure and purity of the final products have been characterized with x-ray diffraction, electron diffraction and dehydration measurements. This simple and rapid method provides a unique case for studying the growth mechanism of polymolybdate nanostructures, and has a promising potential in the mass production of low-cost, pure-phase polymolybdates for a variety of applications.