Convex Polyhedral Au@Pd Core-Shell Nanocrystals with High-Index Facets
Convex Polyhedral Au@Pd Core-Shell Nanocrystals with High-Index Facets
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DOI：
10.1002/anie.201106899
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发表时间：
2012-01-01
影响因子：
16.6
通讯作者：
Han, Sang Woo
中科院分区：
文献类型：
--
作者：
Kim, Dongheun;Lee, Young Wook;Han, Sang Woo
金属纳米晶(NCS)的形貌控制合成是近十年来的一个研究热点，尤其是在催化领域，因为在各种化学反应中，NC的形状会显著影响NCS的催化活性和稳定性[1-4]裸露的具有特定形貌的NC表面可能是催化活性的原因。最近，高指数面结合的NCS的合成引起了人们的特别兴趣，因为这些高指数面通常表现出比低指数面更强的催化性能，因为高指数面具有较高的催化活性原子台阶和扭结。[5]通过电化学和湿化学方法成功地制备了单金属四六面体(THH)、三八面体(TOH)和被高指数面包裹的凹面立方形NCS。然而，在双金属NCS中制备高指数面的合成方法还没有像单金属NCS那样被广泛地探索。最近，在制备具有高指数面的双金属纳米碳管方面取得了有限的成功。利用种子介导法，Huang和他的同事从立方Au种子中制备了Au@Pd核-壳THH NCS。通过在THH和TOH Au NCS上异质外延Pd层，也形成了高指数的多面Pd壳。
The morphology-controlled synthesis of metal nanocrystals (NCs) has been an attractive research area for the past decade, especially in the field of catalysis, because the NC shape can significantly influence the catalytic activity and stability of the NCs in a variety of chemical reactions.[1–4] Exposed NC surface facets with a specific morphology, which can vary with the NC shape, may be responsible for the catalytic activity. Recently, the synthesis of NCs bound by high-index facets has been of particular interest because these high-index facets usually show catalytic properties that are enhanced relative to those of low-index facets because of the high concentration of catalytically active atomic steps and kinks.[5] The successful preparation of monometallic tetrahexahedral (THH), trisoctahedral (TOH), and concave cubic NCs enclosed by high-index facets has been achieved by electrochemical and wet chemical methods.[6–16] However, synthetic approaches to preparing high-index facets in bimetallic NCs have not been explored as extensively as in monometallic NCs. Very recently, limited success has been achieved in the preparation of bimetallic NCs with high-index facets. Using a seed-mediated synthetic method, Huang and co-workers prepared Au@ Pd core–shell THH NCs from cubic Au seeds.[17] High-index faceted Pd shells were also formed through the heteroepitaxial growth of Pd layers onto THH and TOH Au NCs.[18, 19]