首页> 外文期刊>Langmuir: The ACS Journal of Surfaces and Colloids >Rapid transformation from spherical nanoparticles, nanorods, cubes, or bipyramids to triangular prisms of silver with PVP, citrate, and H _2O _2
【24h】

Rapid transformation from spherical nanoparticles, nanorods, cubes, or bipyramids to triangular prisms of silver with PVP, citrate, and H _2O _2

机译:具有PVP,柠檬酸盐和H _2O _2的球形纳米颗粒,纳米棒,立方体或双锥体快速转变为银的三棱柱

获取原文
获取原文并翻译 | 示例
获取外文期刊封面目录资料

摘要

Rapid sphere-to-prism (STP) transformation of silver was studied in aqueous AgNO 3/NaBH 4/polyvinylpyrrolidone (PVP)/trisodium citrate (Na _3CA)/H _2O _2 solutions by monitoring time-dependent surface plasmon resonance (SPR) bands in the UV-vis region, by examining transmission electron microscopic (TEM) images, and by analyzing emitted gases during fast reaction. Roles of PVP, Na _3CA, and H _2O _2 were studied without addition of a reagent, with different timing of each reagent's addition, and with addition of H _2O _2 to mixtures of spheres and prisms. Results show that prisms can be prepared without addition of PVP, although it is useful to synthesize smaller monodispersed prisms. A new important role of citrate found in this study, besides a known role as a protecting agent of {111} facets of plates, is an assistive agent for shape-selective oxidative etching of Ag nanoparticles by H _2O _2. The covering of Ag nanoparticles with carboxylate groups is necessary to initiate rapid STP transformation by premixing citrate before H _2O _2 addition. Based on our data, rapid prism formation starts from the consumption of spherical Ag particles because of shape-selective oxidative etching by H _2O _2. Oxidative etching of spherical particles by H _2O _2 is faster than that of prisms. Therefore, spherical particles are selectively etched and dissolved, leaving only seeds of prisms to grow into triangular prisms. When pentagonal Ag nanorods and a mixture of cubes and bipyramids were used as sources of prisms, rod-to-prism (RTP), cube-to-prism (CTP), and bipyramid-to-prism (BTP) transformations were observed in Ag nanocrystals/NaBH _4/PVP/Na _3CA/H _2O _2 solutions. Shape-selective oxidative etching of rods was confirmed using flag-type Ag nanostructures consisting of a triangular plate and a side rod. These data provide useful information for the size-controlled synthesis of triangular Ag prisms, from various Ag nanostructures and using a chemical reduction method, having surface plasmon resonance (SPR) bands at a desired wavelength.
机译:在AgNO 3 / NaBH 4 /聚乙烯吡咯烷酮(PVP)/柠檬酸三钠(Na _3CA)/ H _2O _2水溶液中,通过监测时变表面等离振子共振(SPR)谱带,研究了银的快速球到棱镜(STP)转变。通过检查透射电子显微镜(TEM)图像,并通过分析快速反应过程中释放出的气体,可以在紫外可见区域中检测气体。研究了PVP,Na _3CA和H _2O _2的作用,而无需添加试剂,每种试剂的添加时间不同以及向球形和棱柱形混合物中添加H _2O _2。结果表明,尽管可以合成较小的单分散棱镜,但无需添加PVP即可制备棱镜。在这项研究中发现的柠檬酸盐的新的重要作用,除了作为板的{111}面的保护剂外,还作为一种辅助剂,用于通过H _2O _2对Ag纳米粒子进行形状选择性氧化蚀刻。通过在加入H _2O _2之前预先混合柠檬酸盐来引发快速的STP转化,必须用羧基覆盖Ag纳米颗粒。根据我们的数据,由于通过H _2O _2进行形状选择的氧化蚀刻,棱镜的快速形成始于球形Ag颗粒的消耗。 H _2O _2对球形颗粒的氧化腐蚀比棱镜快。因此,球形颗粒被有选择地蚀刻和​​溶解,仅留下棱镜的种子生长为三角棱镜。当使用五角形的Ag纳米棒以及立方体和双锥体的混合物作为棱镜的源时,在Ag中观察到杆到棱镜(RTP),立方体到棱镜(CTP)和双锥体到棱镜(BTP)的转变。纳米晶体/ NaBH _4 / PVP / Na _3CA / H _2O _2溶液。使用由三角形板和侧杆组成的标志型Ag纳米结构确认了杆的形状选择氧化蚀刻。这些数据为使用各种化学还原方法从各种银纳米结构中以所需波长具有表面等离振子共振(SPR)带的三角银棱镜的尺寸受控合成提供了有用的信息。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号