Etching and growth: an intertwined pathway to silver nanocrystals with exotic shapes.
Etching and growth: an intertwined pathway to silver nanocrystals with exotic shapes.
复制标题
DOI：
10.1002/anie.200901447
复制
发表时间：
2009
影响因子：
16.6
通讯作者：
Xia, Younan
中科院分区：
文献类型：
--
作者：
Cobley, Claire M.;Rycenga, Matthew;Zhou, Fei;Li, Zhi-Yuan;Xia, Younan
形状控制合成已被证明是控制金属纳米晶体的性质并优化其在催化，[1]电子，[2]传感，[3]生物医学成像，[4]和表面增强拉曼散射（Sers）中的应用的有力手段。[5]通过仔细控制反应条件（例如，反应温度，表面封端，以及试剂和离子种类的浓度），已经合成了具有各种形状的纳米晶体。[6]然而，迄今为止已经制备的大多数纳米晶体是高度对称的，限于大多数金属假定的面心立方晶格。在已经观察到的各向异性形状中，大多数（例如，条、棒和线）是由于沿沿着单一方向的优先生长。[2，7，8]为了增加纳米晶体形状的多样性，我们需要找到新的途径来打破立方对称性，从而迫使生长过程进入其他各向异性模式。最近，籽晶过生长已被证明是形成具有简单和复杂形状和成分的纳米晶体的通用途径，包括纳米颗粒。[9，10]一个典型的例子是银纳米立方体转化为它们的几何双八面体，这是在所有{100}面优先过度生长的结果。[10]在此，我们提出了一种蚀刻诱导生长机制，通过该机制，银纳米立方体被转化为具有奇异形状的纳米晶体，即各向异性截断八面体。在这种情况下，过度生长优先发生在共享一个角的三个相邻面上，由于氧化蚀刻，该角被略微截断（图1）。这种优先的过度生长导致非中心对称的形状，尽管单晶结构被保留。
Shape-controlled synthesis has proven to be a powerful means for controlling the properties of metal nanocrystals and optimizing them for applications in catalysis,[1] electronics,[2] sensing,[3] biomedical imaging,[4] and surface-enhanced Raman scattering (SERS).[5] By careful control of reaction conditions (eg, reaction temperature, surface capping, and concentrations of reagents and ionic species), nanocrystals with a wide variety of shapes have been synthesized.[6] However, the majority of nanocrystals that have been prepared to date are highly symmetric, limited to the facecentered cubic lattice assumed by most metals. Of the anisotropic shapes that have been observed, the majority (eg, bars, rods, and wires) are due to preferential growth along a single direction.[2, 7, 8] To increase the diversity of nanocrystal shapes, we need to find new routes to break the cubic symmetry and thus force the growth process into other anisotropic modes.Recently, seeded overgrowth has been demonstrated as a versatile route to the formation of nanocrystals with both simple and complex shapes and compositions, including bimetallic nanoparticles.[9, 10] A typical example is the transformation of silver nanocubes into their geometric dual octahedrons, as a result of preferential overgrowth at all {100} facets.[10] Herein, we present an etching-induced growth mechanism by which silver nanocubes are transformed into nanocrystals with an exotic shape, namely anisotropically truncated octahedrons. In this case, the overgrowth occurs preferentially on three adjacent faces that share a corner, which is slightly truncated owing to oxidative etching (Figure1). This preferential overgrowth results in a noncentrosymmetric shape, although the single-crystal structure is preserved.
登录
查看更多内容
影响因子：
3.3
作者：
Wiley, Benjamin J.;Im, Sang Hyuk;Xia, Younan
通讯作者：
Xia, Younan
影响因子：
16.6
作者：
Xia, Younan;Xiong, Yujie;Lim, Byungkwon;Skrabalak, Sara E.
通讯作者：
Skrabalak, Sara E.
影响因子：
2.8
作者：
Siekkinen, Andrew R.;McLellan, Joseph M.;Xia, Younan
通讯作者：
Xia, Younan
影响因子：
10.8
作者：
McLellan, Joseph M.;Li, Zhi-Yuan;Xia, Younan
通讯作者：
Xia, Younan
影响因子：
1.8
作者：
Burt, JL;Elechiguerra, JL;Jose-Yacaman, M
通讯作者：
Jose-Yacaman, M