Aliyah Kinanti, Lyu Jieli, Goldmann Claire, Bizien Thomas, Hamon Cyrille, Alloyeau Damien, Constantin Doru
Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.
SWING beamline, SOLEIL Synchrotron, 91192 Gif-sur-Yvette, France.
J Phys Chem Lett. 2020 Apr 16;11(8):2830-2837. doi: 10.1021/acs.jpclett.0c00121. Epub 2020 Mar 27.
Rational nanoparticle design is one of the main goals of materials science, but it can only be achieved via a thorough understanding of the growth process and of the respective roles of the molecular species involved. We demonstrate that a combination of complementary techniques can yield novel information with respect to their individual contributions. We monitored the growth of long aspect ratio silver rods from gold pentatwinned seeds by three techniques (small-angle X-ray scattering, optical extinction spectroscopy and liquid-cell transmission electron microscopy). Exploiting the difference in reaction speed between the bulk synthesis and the nanoparticle formation in the TEM cell, we show that the anisotropic growth is thermodynamically controlled (rather than kinetically) and that ascorbic acid, widely used for its mild reductive properties, plays a shape-directing role, by stabilizing the {100} facets of the silver cubic lattice, in synergy with the halide ions. This approach can easily be applied to a wide variety of synthesis strategies.
合理的纳米颗粒设计是材料科学的主要目标之一，但只有通过深入了解生长过程以及所涉及分子物种的各自作用才能实现。我们证明，互补技术的结合可以产生关于它们各自贡献的新信息。我们通过三种技术（小角X射线散射、光学消光光谱和液池透射电子显微镜）监测了从金五重孪晶种子生长出的长径比银棒的生长情况。利用TEM池中本体合成与纳米颗粒形成之间的反应速度差异，我们表明各向异性生长是由热力学控制的（而非动力学控制），并且广泛因其温和还原性质而使用的抗坏血酸，通过与卤离子协同作用稳定银立方晶格的{100}面，发挥形状导向作用。这种方法可以很容易地应用于各种各样的合成策略。
