Intercalation Studies Of Layered Perovskite Oxides

The layered perovskite oxide is an important solid functional material. Itsapplications are largely expanded as the layer ,active center of chemical reaction ,due to itsunique layered structure. It is widely used in the photocatalysis, ferroelectricity,superconductivity, and semiconductor giant magnetoresistance. This paper focuses on thesynthesis and the intercalation reaction with alkyl amines and CuCl+of three layeredperovskite oxides.1. The synthesis of layered perovskite oxidesThree layered perovskite oxides were synthesized by different methods: single-layerRuddlesden-Popper phase compound NaLaTiO4, three-layer Ruddlesden-Popper phasecompound K2La2Ti3O10and double-layer Dion-Jacobson phase compound KLaNb₂O₇.The optimum conditions for the synthesis of these three layered perovskite oxide arestudied: The calcination temperature should be controlled at 900℃, and the calcination timeshould be 2h when NaLaTiO4was synthesized with high temperature solid method;, K shouldbe maintained in 80% excess ,and the precursor must be calcined at 900℃for 4h whenK2La2Ti3O10was synthesized with the stearic acid method; The precursor should be placedunder 1100℃for 6h when KLaNb₂O₇was synthesized with stearic acid method .2. The study of intercalation of the alkylamine to the layered perovskite oxidesThe impact of the concentration of H⁺and reaction time on intercalation of alkyl amineswas studied : the concentration of H⁺and reaction time affected the intercalation ofalkylamines, mainly through changing the reactivity of the gap between two layers. Theresults showed that H⁺inserted into the the gap between two layers of perovskite oxidesr inthe form of H3O+. With the growth of the concentration of H⁺and the reaction time, thecontent of H2O is gradually decreased with chemical reactivity of the layer gradually reducedand the intercalation of alkylamine became more difficult.The intercalation reaction of alkylamine to three layered perovskite oxides was studied. Propylamine, butylamine, octylamine, dodecylamine can be inserted to the gap between twolayers of KLaNb2O7; only positive octylamine can be inserted into K2La2Ti3O10, but thereaction was incompleted; all four amines can not be inserted into the gap between two layersof NaLaTiO₄. The results showed that: the acidity of the perovskite’s layer is the mostimportant factor of the alkylamine intercalation, the alkaline of alkylamines, sterichindrance and the structure of the alkylamines also affected the intercalation of alkylamine tolayered perovskite oxides.3. Intercalation studies of CuCl⁺to layered perovskite oxidesThe intercalation of CuCl⁺to two layered perovskite oxides, NaLaTiO₄and KLaNb₂O₇was studied. The structural was characterized by X-ray powder diffraction ,analysis showedthat: CuCl⁺was successfully inserted into the gap between two layers of NaLaTiO₄andKLaNb2O7, forming （CuCl）LaTiO₄and （CuCl）LaNb₂O₇. The results of structural analysisshowed that both of （CuCl） LaTiO₄ and （CuCl）LaNb₂O₇are Aurivillius phase, belong to thetetragonal symmetry, I4/mmm space group. The unit cell parameters of （CuCl）LaTiO₄: a = b =3.87（?） , c = 21.58 （?） , the quality points is 2; unit cell parameters of （CuCl）LaNb₂O₇: a = b =3.88（?） , c = 22.14 （?）, the quality points is 2.