Formation of tubular BaTiO3 nanoparticle assembly through the Kirkendall effect using Na2Ti3O7 nanowires as template

We report the solvothermal synthesis of tubular BaTiO3 nanoparticle assembly in ethanol/water mixed solvent system using Na2Ti3O7 nanowires as template. The obtained tubular BaTiO3 nanoparticle assembly, with a straight interior shell, is constructed by nanoparticles with diameters of 150–400 nm on the outer surface. The tubular BaTiO3 nanoparticle assembly retains the one-dimensional characteristic inherited from the precursor Na2Ti3O7 nanowires during solvothermal process. The formation mechanism of the hollow interior of tubular BaTiO3 nanoparticle assembly is deriving from nanoscale Kirkendall effect, and the growth of nanoparticles on the outer surface with different sizes is controlled by the Ostwald ripening process, resulting in larger meaning outer diameter.