二维氧化钛纳米页

单层氧化钛纳米页(titania nanosheets)是一种厚度仅为0.7 nm的新型二维纳米材料,具有许多不同于块体氧化钛的优异性质,如:高各向异性、单晶性质、胶体和聚电解质特性、大比表面积、高表面能和量子尺寸效应等。在光电转换、磁光效应、高介电常数器件、电化学能量储存、湿敏传感器、自清洁和光催化等领域极具应用前景。本文首先总结了氧化钛纳米页的基本性能,如:光吸收性能、光致发光性能、光电化学性能、光诱导亲水性能和晶相转变温度差异等,概述了氧化钛纳米页的制备及组装方法,接着分别以薄膜片、纳米管、中空微球、超薄多层复合薄膜为代表,介绍了氧化钛纳米页组装得到的新型材料及其特点,然后介绍了氧化钛纳米页的掺杂改性,从拓宽光吸收带边、提高电子迁移速率和提高磁光效应三个角度,归纳总结了离子掺杂与氧化钛纳米页性能之间的关系,最后对氧化钛纳米页未来的研究发展趋势提出了展望。

Two-Dimensional Titania Nanosheets

Titania nanosheets is one kind of novel two-dimensional materials with single layer of 0.7 nm thickness,which endows it many special properties different from bulk titania,such as high anisotropy,single crystal property,colloid and polyelectrolyte properties,large specific surface area,high surface energy,quantum size effects,etc.Potential applications can be expected in photon-to-electron conversion,magnetooptical effects,high permittivity devices,electrochemical energy storage,humidity-sensitive sensors,self-cleaning and photocatalysis fields.In this review,the intrinsic properties of titania nanosheets,such as optical absorption,photoluminescence,photon-to-current conversion,photoinduced hydrophilicity and the difference of crystal transformation temperature,are summarized,and the preparation and assembly methods of titania nanosheets are introduced.Then,these new assembled materials and their properties are reviewed in detail by using thin flakes,nanotubes,hollow microspheres and complex films as representations.Afterwards,the modifications of titania nanosheets by doping with impurity ions are also introduced,and the relations between ions doing and properties of titania nanosheets are discussed from three aspects: extending the absorption edge of light,improving electron transfer rate and enhancing magnetooptical response.Finally,the future research trends of titania nanosheets are also suggested.