One-step template-free synthesis of BaSb2O6 micro-flowers and their associated photocatalytic activity

The rose-flower-like BaSb2O6 (R-BaSb2O6) and marigold-flower-like BaSb2O6 (M-BaSb2O6) have been successfully prepared by a simple hydrothermal method avoiding high temperature, templates, catalysts, surfactants, or organic solvents. Their structures and morphologies have been investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and selected-area electron diffraction. Ba/Sb molar ratio and pH values in the precursor play significant roles in building two kinds of flower-like BaSb2O6. Time dependent experiments reveal the possible formation mechanisms of the BaSb2O6 microstructures. When used as a photocatalyst, the M-BaSb2O6 exhibits the best photocatalytic activity among R-BaSb2O6, M-BaSb2O6 and BaSb2O6 synthesized by solid state reaction. The morphology of M-BaSb2O6 results in the large BET specific surface area and unique light propagation mode, which greatly improve the interaction among photons, organic compounds and photocatalyst, and thus enhance photocatalytic activity. The photocatalytic stability experiments demonstrate the sufficient stability of M-BaSb2O6 during the photocatalytic process.