Layered Tungstic Acid/Alkylamine Hybrids and Their Decomposed Products: Intercalation Reactions and Morphology Control

Abstract

We introduced a "Chimie Douce" approach to synthesize layered tungstic acid/alkylamine hybrid nanostructures (nanotubes or nanosheets) at room temperature using Bi₂W₂O₉ as start materials. Layered H₂W₂O₇ with interlayer H₂O, derived by leaching the [Bi₂O₂] sheets of Bi₂W₂O₉, was intercalated with alkylamines (C_nH_2n+1NH₂, n = 4,5,7,8,12,14,16,18) in non-aqueous solutions. By carefully choosing the reaction media and reactant ratios, the organic/inorganic hybrid nanostructures with controllable morphologies could be achieved, and the corresponding tungsten oxide nanocrystals were obtained by decomposing the organic species at elevated temperature or in concentrated nitric acid. The proposed approach is characteristic of high efficiency and low cost.