Controllable synthesis and formation mechanism of Bi4Ti3O12 nano- and micro-structures by a solvothermal method

Novel hierarchical Bi4Ti3O12 (BIT) micro-cross spheres were prepared by a solvothermal process with surfactant assistance. Experimental results show that the hierarchical BIT micro-cross spheres exhibit a mono-dispersed morphology with a diameter of about 5 μm. And they consist of nano-sheets which assemble into a cross intercalated structure. Moreover, the morphological evolution process indicates that the type and concentration of surfactant play important roles in the shape controlled synthesis and cetyltrimethylammonium bromide is important in determining the self-assembling process of BIT micro-cross spheres. In addition, UV/vis absorption spectra show that the as-synthesized BIT samples have a slightly red-shift behavior and exhibit different band gaps with different morphologies.