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, Bi₂Ananb₃O₁₂ (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 HCI at room temperature. Preservation of the structure of the perovskite-like slabs and contraction in the c 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_0.8Bi_0.2NaNb₃ O₁₀] (A = Sr or Ca) by inductively coupled plasma emission spectroscopy and thermogravimetry. The acid-treated product H_1.8[Sr_0.8Bi_0.2-NaNb₃ O₁₀] was capable of accommodating n-alkylamines in the interlayer space, which is in good agreement with the proposed layered structure.