Investigation of factors influencing the formation of Tungstate-based inorganic-organic hybrid nanobelts/nanotubes

Tungstate-based inorganic-organic hybrid nanobelts/nanotubes were synthesized in a system of H₂W₂O₇· xH₂O/n-octylamine/heptane (n-octylamine:H₂W ₂O₇·xH₂O molar ratio: 30), and the effects of the volume ratios of heptane to K-octylamine and the amounts of interlayer water in H₂W₂O₇·xH ₂O on the formation behavior of the hybrids were investigated. The belt/tubelike hybrids obtained were 10-20 μm in length and 200-500 nm in apparent diameter. Large volume ratios of heptane to n-octylamine not only enhanced the degree of the long-range order of the lamellar structures in the hybrids, but they also improved the morphologic uniformity of the hybrids. The existence of interlayer water in H₂W₂O₇· xH₂O was indispensable to the formation of tungstate-based inorganic-organic hybrid nanobelts/nanotubes. The amounts of interlayer water in H₂W₂O₇·xH₂O varied over a wide range (x, from 0.85 to 4.1), had a neglectable effect on the morphology of the tungstate-based nanophase hybrids, but exerted a remarkable influence on the rate of the reaction of H₂W₂O₇·xH ₂O with n-octylamine in the heptane solvent. The larger the amount of interlayer water, the more rapid the reaction rate.