Microwave-assisted solvothermal synthesis and growth mechanism of WO3·(H2O)0.33 hierarchical microstructures

Abstract

WO₃·(H₂O)_0.33 hierarchical microstructures such as micro-nutlets, micro-flowers, and micro-discs have been successfully prepared via a facile microwave-assisted solvothermal route employing Na₂WO₄·2H₂O and hydrochloric acid as precursors and disodium ethylenediaminetetraacetic (Na₂H₂EDTA) as a structure-directing agent. The products have been characterized by X-ray powder diffraction (XRD), energy dispersive X-ray analysis (EDS) scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The influences of reaction time, temperature, the volume ratio of water and glycerol, and the amount of Na₂H₂EDTA and hydrochloric acid on the morphologies have been studied in detail. A possible growth mechanism was proposed.