Nanosphere Synthesis and the Impact of Curvature on Molecule Adsorption

有了这个奖项，化学系的大分子，超分子和纳米化学计划资助弗吉尼亚大学的Petra Reinke教授开发由碳（碳化物）化学结合到金属上的新型超小催化剂颗粒。这些粒子的直径小于十亿分之几米，具有广泛的潜在应用，从催化，其中碳化物基粒子可以替代昂贵的贵金属，到分子电子学。该项目解决了两个挑战，这是使用基于碳化物的纳米颗粒的关键瓶颈：首先，合成具有窄尺寸分布的稳定的基于碳化物的纳米颗粒，可以调整以最大化性能，其次，了解几何和电子结构对化学反应性的影响。外展活动，和基于网络的，学生设计的纳米技术资源的开发与研究计划相结合。纳米粒子的曲率，作为分子吸附几何形状的控制参数，有可能作为一个强大的工具，在驱动自下而上组装。本提案针对分子尺寸变得与其吸附的金属或半导体纳米颗粒的直径相当的尺寸范围。拟议的工作针对两个领域，第一，合成稳定的超小纳米粒子（纳米球）作为模型系统，第二，分子吸附的研究。纳米球是由富勒烯（作为碳支架）和金属基底之间的固态反应形成的。纳米球的形成机制将被研究，以控制组成，键合和表面结构。纳米球的合成机制，以及这些纳米球上的吸附晕苯将主要研究与扫描隧道显微镜和光谱。基于同步加速器的光电子能谱将被应用于阐明键合和吸附诱导的分子变化。实验工作将与（i）统计图像分析，（ii）曲面尖端卷积的模拟，以及（iii）用DFT（密度泛函方法）模拟金属分子相互作用和纳米球形成相结合。

With this award, the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry is funding Professor Petra Reinke at the University of Virginia to develop novel, ultrasmall catalyst particles that consist of carbon (carbides) chemically bound to a metal. These particles, with diameters of less then a few billionths of a meter, havea wide range of potential applications, from catalysis, where carbide-based particles can substitute for expensive noble metals, to molecular electronics. The project addresses two challenges, which are critical bottlenecks for the use of carbide-based nanoparticles: First, the synthesis of stable carbide-based nanoparticles with a narrow size distribution, which can be adapted to maximize performance, and second, understanding the impact of geometric and electronic structure on chemical reactivity. Outreach activities, and the development of a web-based, student-designed nanotechnology resources are integrated with the research program. Nanoparticle curvature, as a control parameter for molecule adsorption geometry, has the potential to function as a powerful tool in driving bottom-up assembly. The present proposal targets the size regime where molecule size becomes comparable to the diameter of a metallic or semiconducting nanoparticle on which it is adsorbed. The proposed work targets two areas, first, the synthesis of stable ultra-small nanoparticles (nanospheres) as model systems, and, second, the study of molecule adsorption. The nanospheres are formed by a solid-state reaction between fullerenes, which serve as the carbon scaffold, and a metal substrate. The mechanism of nanosphere formation will be studied to control composition, bonding and surface structure. The mechanisms of nanosphere synthesis, and the adsorption of coronene on these nanospheres will be studied mainly with scanning tunneling microscopy and spectroscopy. Synchrotron-based photoelectron spectroscopy will be applied to elucidate bonding, and adsorption-induced changes in the molecule. The experimental work will be integrated with (i) statistical image analysis, (ii) simulation of tip convolution for curved surfaces, and (iii) simulation of metal-molecule interaction and nanosphere formation with DFT (density functional methods).