The Study On The Systhesis Of The Intercalation Compounds With The KTiNbO₅ As A Precusor

Recently, in the research on how to design and synthesize the novel intercalation-materials, layered compounds have become important precursors. Based on the layered structure of the compounds, some novel intercalated compounds can be synthesized with the intercalation technology. These intercalated compounds become more attractive functional materials due to the great potential application in the fields of the photoelectric conversion devices, catalysts, chemical or biological sensors. Many inorganic layered compounds such as titanate, niobate etc, are not easy to be exfoliated in water due to its strong electrostatic interaction between layers and interlayered ions. However, we can increase the interlayer distance of the layered coompounds with the chemical and physical method so that some compositions with big size can be inserted into the interlayer of the compounds.Among the so many inorganic host materials, titanium oxides and niobium oxides which have two dimensional structures have attracted great scientists interest. Compared with other layered compounds, these compounds have more advantages in the photo-response and electronic conductivity, because these compounds have the high negative charge density, the high anisotropy, and very ultrathin layers. KTiNbO₅ was firstly systhesised by Wadsley in 1962. KTiNbO₅ consists of corner-sharing and edge-sharing octahedral units of TiO6 and NbO6, by which a layered structure is formed. K+ ions are located between the layers to compensate the negative charge of the layers. The unit cell of the compound is orthorhombic with a=0.6447nm, b=0.3797nm and c=1.8431nm. In this thesis, KTiNbO₅ was used as the precursor, a series of misfit-layered transition metal titanate oxides have been synthesized, and the synthesis conditions are investigated. The compounds have been characterized with XRD, IR, TG-DTA, SEM, TEM, SAED,and EDS.We have synthesized KTiNbO₅ according to the literature. The optimum experimental condition is heating the reactant at the temperature of 1100℃for 24 hours. The optimum condition for the preparation of HTiNbO₅ (products of ion-exchange) is ion-exchanging of KTiNbO₅ in 2mol/L HCl for one day in the room temperature. The reactions of delamination of HTiNbO₅ have been studied, in which different kinds of amine have be used. The optimum exfoliation condition is: n正丙胺:nHTiNbO₅=60, hydrothermal treatment at 120℃for two days.By using KTiNbO₅ as a precursor, magnesium titanium niobium oxide, [Mg(OH)_0.185(H₂O)_1.815])_0.551·(TiNbO₅)·2.468H₂O (MgTiNbO), has been synthesized by hydrothermal method. This compound has fluorescence properties. In addition, there are two sublattices in this compound, i.e. the orthorhombic sublattice of TiNbO₅- and the other pseudo- hexagonal sublattices of [Mg(OH)_0.185(H₂O)_1.815]_1.815+, and these sublattices are incommensurate along one direction in ab plane. The TiNbO₅^- orthorhombic sublattice parameters are aa=6.33A,ba=3.77A,ca=11.28A,and,αa=βa=γa=90°. The [Mg(OH)_0.185(H₂O)₉1.815)]_1.815+ orthorhombic sublattice parameters are ab=18.43A,bb=6.33A,cb=11.28A,andαb=βb=γb=90°.Manganese titanium niobium oxide compound MnTiNbO—[MnO0.371 (H₂O)_1.629]_0.307·(TiNbO₅)·0.275H₂O has been hydrothermally synthesized by using KTiNbO₅ as a precursor.