A review of significant factors in the synthesis of hetero-structured dumbbell-like nanoparticles  

异质哑铃型纳米颗粒合成中的关键因素(英文)

作　　者：黄启福[1] 李文志[1] 林其钊[1] 皮冬 胡超[1] 邵春宇[1] 张海涛[1] 

机构地区：[1]中国科学技术大学工程科学学院热科学和能源工程系,安徽合肥230026

出　　处：《Chinese Journal of Catalysis》2016年第5期681-691,共11页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China(51376171);Science and Technological Fund of Anhui Province for Outstanding Youth(1508085J01)~~

摘　　要：This paper reviews several important factors that influence the synthesis of dumbbell‐like nanoparticles,which can significantly enhance the catalyst activity in catalytic combustion. The dumbbell‐like nanoparticles discussed in this article refer to a hetero‐structure with two nanoparticles of different materials in contact with each other. This nanostructure can be considered as a special intermediate between individual spherical nanoparticles and a core–shell nanostructure. Therefore,the synthesis of dumbbell‐like nanoparticles is more difficult than other structures. The controllability of the synthesis process, the nanoparticle size and size distribution, and the morphology of the final products depend on many factors： the seed size and size ratio could be used to influence the controllability of epitaxial growth. The component sizes and size distribution could be varied by carefully controlling the reaction temperature and reaction time. The morphology of the dumbbell‐like nanoparticles is closely related to the solvent polarity, the precursor ratio, the lattice mismatch between the two components, and the surfactant concentration. Some related synthesis methods are also briefly introduced in each section to facilitate understanding. This summary will benefit the development of new dumbbell‐like nanoparticles with various components, which have great potential in catalytic combustion of more dysoxidizable gases.哑铃型纳米颗粒由一种包含强相互作用的异质结构成,它两端是不同物质的纳米颗粒.这两种不同功能的纳米颗粒紧密相连,形成一种哑铃形的外观.这种结构的纳米颗粒在电子、磁性、光学及催化等方面有着不同于单一组分纳米颗粒的独特性质,因此受到人们广泛关注.哑铃型纳米颗粒的这些独特性质是由两种物质交界面处的电子转移引起的,得益于较强的界面相互作用,两种物质都可以通过界面处的电子转移得到改良,使得这种结构的催化剂在较低温度下催化氧化有机废气时活性很高.以CO氧化反应为例,Au纳米颗粒通常情况下对该反应没有催化活性,但是被负载到金属氧化物上面以后,却表现出了很高的催化活性.这正是氧化物载体与Au纳米颗粒之间电子传输的结果.通常在核壳结构中,核心物质以及两种物质的交界面都被外壳所包裹,而哑铃型结构当中的两种物质的功能面以及它们之间活泼的交界面均可以充分地暴露在反应物中,从而极大提升了其催化效果.这种独特的结构优势也在疾病诊断与治疗中的多功能探针上得到了广泛应用.由于哑铃型结构的两种物质的纳米颗粒相对位置是固定的,当用作催化剂时可以发挥出很好的抗烧结性能,还可使这两种物质更协调地均匀分布.因此哑铃型结构催化剂不仅催化活性更高,而且在较高温度下具有较高的稳定性.哑铃型结构可以看作是独立纳米颗粒与核壳型纳米颗粒之间的一种中间状态,它通常是由一种物质的纳米颗粒在另一种种子颗粒上面经过外延生长得到的.这与核壳结构纳米颗粒的合成很相似,但是必须准确地控制成核过程,使得成核可以各向异性地发生在种子颗粒的某一个晶面上.而在核壳结构的合成中,这一成核过程是均匀分布的.所以在制备哑铃型结构纳米颗粒时,很重要的就是要促进非均质成核,同时抑制�

关 键 词：Dumbbell-like nanoparticle Catalyst synthesis Catalytic combustion Catalytic oxidation 

分 类 号：O643.36[理学—物理化学] TB383.1[理学—化学]