A recyclable sacrifice-template route to prepare Al2O3 hollow microspheres

Abstract A novel route to prepare Al 2 O 3 hollow microspheres with a diameter of about 6 μm is presented by the way of using CaMg(CO 3 ) 2 microspheres as the recyclable sacrifice-template and aqueous solution of Mg(NO 3 ) 2 and Ca(NO 3 ) 2 as dispersant. The dispersant can not only control the reaction rate of ion-exchange to synthesize Al 2 O 3 hollow microspheres, but also act as a reactant to recycle the templates. Moreover, the as-obtained Al 2 O 3 hollow microspheres possessed a surface area of 214.8 m 2  g −1 and a pore volume of 0.9117 cm 3  g −1 , which are higher than many reported porous Al 2 O 3 materials. These advantages make this route economical and efficient to prepare Al 2 O 3 hollow microspheres, and promising in large-scale preparation of other metal oxides hollow structures.