Conversion of Aurivillius phases Bi2ANaNb3O12 (A = Sr or Ca) into the protonated forms of layered perovskite via acid treatment

Protonated forms of layered perovskites were derived from Aurivillius phases, Bi(2)ANaNb(3)O(12) (A = Sr or Ca), by the substitution of bismuth oxide sheets with protons via acid treatment. The conversion into the protonated forms was achieved easily using 6 M HCl at room temperature. Preservation of the structure of the perovskite-like slabs and contraction in the e axis were confirmed by X-ray and electron diffraction analysis as well as by transmission electron microscopy. The compositions of the resulting products were determined to be H-1.8[A(0.8)Bi(0.2)NaNb(3)O(10)] (A = Sr or Ca) by inductively coupled plasma emission spectroscopy and thermogravimetry. The acid-treated product H-1.8[Sr0.8Bi0.2NaNb3O10] was capable of accommodating n-alkylamines in the interlayer space, which is in good agreement with the proposed layered structure.