Synthesis of Hierarchical Flower-like AlOOH and TiO2/AlOOH Superstructures and their Enhanced Photocatalytic Properties

Hierarchical flower-like boehmite superstructures (HFBS) composed of intermeshed nanoflakes were synthesized by hydrothermal treatment from as-formed aluminum hydroxide microspheres, which were prepared by adding aluminum spheres into a sodium metaaluminate solution. A two-step mechanism for the formation of HFBS is proposed, which involves initial formation of Al(OH)(3) microspheres followed by their transformation to AlOOH. The as-prepared HFBS superstructures call be easily transformed into gamma-Al2O3 Superstructures Without morphology change by calcination at 500 degrees C for 2 h. Furthermore. the TiO2 nanoparticles can homogeneously deposited oil the surface of HFBS by the vapor-thermal method. The TiO2 nanoparticles coated on HFBS showed higher photocatalytic activity for photocatalytic decolorization of rhodamine B (RhB) aqueous Solution than Degussa P25 (P25) and TiO2 powders prepared at the same experimental conditions, A significant enhancement of the photocatalytic activity can be related to several factors, including hierarchical porous structure, high dispersion of TiO2 particles, and the increased ligh-harvesting abilities. Moreover, TiO2-coated HFBS can settle naturally within 5 min. which is beneficial for separation and recycling, considering their future applications in wastewater treatment.