New layered materials containing Ti and Nb and their unique properties

层状氧化物材料具有高效光催化裂水、超导、电化学插层等独特性能。钛、铌层状氧化物在溶液中可以剥离为纳米片层。我们发现，通过在溶液中混合纳米片和大尺寸的阳离子，可以很容易地制备出一些有趣的层状材料。这项技术被称为静电自组装沉积(ESD)方法。本课题主要通过ESD方法制备了一些新型的含钛或含Nb的层状氧化物，其独特的电化学性质如下：1.银插层氧化物的独特电化学性质银插层氧化物与银发生了强烈的氧化还原反应，其中银原子/银+离子的电化学反应发生在层间空间。这种独特而简单的电化学反应是通过通过主体层的隧道电子交换以及质子在中间层中的迁移而发生的。2.Photocata…在可见光照射下，由于Ru络合物在可见光照射下起到光催化作用，因此层状氧化物与Ru配合物在可见光照射下起到光催化作用。3.在含乙醇溶液中，Nb纳米片上的光电流较大，与其他纳米片相比，Nb基质氧化物的单纳米片上存在较大的乙醇氧化所致的光电流。这主要是由于基质纳米片中的空穴和电子没有复合所致。与其他纳米片相比，Nb基质纳米片的导带边具有较高的能级位置也是另一个原因。4.稀土离子插层层状氧化物的光致发光研究与Eu离子插层在一起的水分子促进了从主体层到Eu层的能量转移而产生的发射。这是基于夹层中水分子的特殊成键状态，就像在冰中一样。较少

Layered oxide materials have many unique properties such as photocatalysis of water split with high efficiency, superconduction, and electrochemical intercalation, etc. Ti and Nb layered oxides can be exfoliated to host nano-sheet in solution. We have developed that some interesting layered materials can be easily prepared by mixing nano-sheets and cations with large size in solution. This technique is called to ESD (Electrostatic Self-assembly Deposition) method. In this project, some new layered oxides containing Ti or Nb are prepared mainly by ESD method, and their unique properties are demonstrated as follows.1.Unique electrochemical properties of Ag intercalated oxidesLayered oxides intercalated with Ag showed sharp redox reaction where electrochemical reaction of Ag atom/ Ag+ ion occurs in the interlayer space. This unique and simple electrochemical reaction occurs with tunneling electron exchange through the host layer together with proton migration in the interlayer.2.Photocata … More ysis under visible light illuminationLayered oxides intercalated with Ru complex were acted as photocatalyst under visible light illumination, because the Ru complex acts under visible light illumination. Fixation of Ru complex in the interlayer is necessary for practical use.3.High photocurrent at Nb nano-sheet in solution containing alcoholHigh photocurrent due to alcohol oxidation was observed on mono-nano-sheet of Nb host oxide compared with other nano-sheet. The main reason is based on the non-recombination of hole and electron in the host nano-sheet. High energy position of the conduction band edge of Nb host nano-sheet compared with other nano-sheet is also another reason.4.Photoluminescence of layered oxides intercalated with lanthanide cationsTi layered oxide intercalated with Eu cation showed photoluminescence with high intensity. Water molecules intercalated together with Eu cation promotes the emission due to energy transfer from host layer to Eu. This is based on special bonding state of intercalated water molecules in the interlayer like in ice. Less