A conversion route towards tubular SiO2 using rod-like BaSiF6 as a novel template

A simple hydrothermal reaction between Ba(NO3)2 and K2SiF6 results in the formation of 1D rod-like BaSiF6. The BaSiF6 rods can act as efficient precursors for production of tubular SiO2 by hydrothermal reaction in alkaline solutions. Powder X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high resolution electron microscopy (HRTEM), and field emission scanning electron microscopy (FESEM) were used to characterize the phase and morphology of the final product. The experiments indicated the amount of NaOH, reaction temperature, and reaction time played important roles in the transformation process. A possible growth mechanism of tubular silica was proposed.