Park Yangsun, Lee Young Wook, Kang Shin Wook, Han Sang Woo
Department of Chemistry and KI for the NanoCentury, KAIST, Daejeon 305-701, Korea.
Nanoscale. 2014 Aug 21;6(16):9798-805. doi: 10.1039/c4nr02034k.
Bimetallic nanocrystals (NCs) enclosed by high-surface energy facets have been of enormous interest due to their pronounced catalytic performance in numerous chemical and electrochemical reactions. However, it remains a significant challenge to develop a facile method to synthesize bimetallic NCs with high-surface energy facets in the form of finely tuned structures due to the difficulties in manipulating the nucleation and growth kinetics of NCs in the presence of multiple metal precursors. In the present work, a facile one-pot aqueous synthesis method is developed for the production of bimetallic Au@Pd core-shell NCs with an unusual truncated hexoctahedral (THOH) shape without pre-synthesized seeds. The THOH Au@Pd NCs are bound by multiple high- and low-index facets. The formation of this unique structure is realized through co-reduction of Au and Pd precursors under precisely controlled kinetic conditions. The prepared THOH NCs exhibit a prominent electrocatalytic performance for ethanol oxidation, which is attributed to their characteristic structural features. This study significantly expands the understanding of NC growth and will lead to fabricating novel nanomaterials with desired morphologies and functions.
由高表面能晶面包围的双金属纳米晶体（NCs）因其在众多化学和电化学反应中显著的催化性能而备受关注。然而，由于在多种金属前驱体存在的情况下难以控制NCs的成核和生长动力学，开发一种简便的方法来合成具有精细调控结构形式的高表面能晶面的双金属NCs仍然是一项重大挑战。在本工作中，开发了一种简便的一锅水相合成方法，用于制备具有不寻常截顶六八面体（THOH）形状的双金属Au@Pd核壳NCs，无需预先合成种子。THOH Au@Pd NCs由多个高指数和低指数晶面包围。这种独特结构的形成是通过在精确控制的动力学条件下共还原Au和Pd前驱体实现的。制备的THOH NCs对乙醇氧化表现出显著的电催化性能，这归因于其特征结构特征。本研究显著扩展了对NC生长的理解，并将导致制造具有所需形态和功能的新型纳米材料。
