The catalytic activity and mechanical stability of hollow nanoparticles (nanocages) of different sizes, shapes and shell structure

来自佐治亚理工学院的Mostafa A. El-Sayed教授获得了大分子、超分子和纳米化学项目的奖励，研究中空金属纳米颗粒（纳米笼）的催化活性和机械稳定性。它们有单壳或双壳，比固体纳米颗粒表现出更有效的催化性能。关于这种增强是由约束效应引起的说法正在研究中。在研究中有几个目标：1。比较气相反应和溶液反应中的笼形效应。2. 开发等离子体增强SERS技术，用于检测金或银纳米笼腔内发生的反应中的瞬态反应中间体。3. 研究纳米笼表面粗化及改变其形状和尺寸对反应速率的影响。4. 通过双壳中空纳米粒子的合成进展、电子转移反应与核壳纳米粒子的比较以及合金效应（两个金属壳层之间的原子内扩散）的研究来探索双壳中空纳米粒子的催化性能。利用飞秒泵浦探测技术，半导体-金属杂化双壳纳米粒子被用于研究光催化和超快电子转移动力学。5. 采用该小组的超快晶格相干振荡方法确定具有等离子体纳米壳的纳米笼的机械稳定性，作为所使用金属，壳厚度，合金化工艺程度的函数。催化是一个价值9000亿美元的领域，负责90%以上的消费材料的更有效生产。纳米催化是一个迅速发展的领域，将对化工生产、可持续能源、材料化学等众多技术领域产生重要影响。这里提出的研究有可能找到具有工业重要性的新催化剂。这项研究将不仅限于纳米催化研究，还将包括引入一种基于飞秒动力学的新技术，以测量所使用的纳米笼的机械强度。这项工作是由他们的激光动力学实验室进行的，该实验室经常为需要测量纳米粒子系统中的超快动力学的其他科学家和工程师提供合作和帮助。实验室在培养博士后、研究生和本科生方面非常活跃。通常一半的本科生，包括NNIN和/或REU暑期项目的本科生，是女性或少数民族。该小组与这些邻近的少数民族学校的教员保持着良好的关系，PI定期在那里举办研讨会，而激光动力学实验室也在乔治亚理工学院的实验室名单上，对当地社区的学生和教师团体开放。

Prof. Mostafa A. El-Sayed from Georgia Institute of Technology is supported by an award from the Macromolecular, Supramolecular and Nanochemistry program to study catalytic activity and mechanical stability of hollow metal nanoparticles (nanocages). These come in either single or double shells and exhibit more efficient catalytic properties than solid nanoparticles. The suggestion that this enhancement arises from confinement effects is being investigated. There are several objectives in the research: 1. To compare the cage effect in gaseous reactions with those in solution. 2. To develop a plasmonically enhanced SERS technique to detect transient reaction intermediates in reactions occurring within the cavity of gold or silver nanocages. 3. To study the effects of roughening the nanocage surface and changing its shape or size on the reaction rate. 4. To explore the catalytic properties of the double shell hollow nanoparticles through developments in synthesis, comparison of electron transfer reactions with those on core-shell nanoparticles, and investigations of the alloying effect (intra-atomic diffusion between the two metallic shells). Semiconductor-metal hybrid double shell nanoparticles are being used to study photocatalysis and ultrafast electron transfer dynamics using femtosecond pump-probe techniques. 5. The mechanical stability of the nanocages having plasmonic nanoshells is determined using the group's ultrafast lattice coherent oscillation method as a function of the metals used, shell thickness, degree of the alloying processCatalysis is a $900 billion field and is responsible for the more efficient production of over 90% of consumer materials. Nanocatalysis is a rapidly expanding field and could have important impacts on numerous technical fields such as chemical production, sustainable energy, and materials chemistry. The research proposed here has the potential to find new catalysts of industrial importance. The research will not be limited to nanocatalysis research, but will include introducing a new technique based on femtosecond dynamics to measure the mechanical strength of the nanocages used. This work is being carried out by their Laser Dynamics Lab, which frequently provides collaboration and help to other scientists and engineers needing to measure ultrafast dynamics in nanoparticle systems. The lab is very active in educating postdoctoral researchers, graduate students, and undergraduate students. Usually half of the undergraduates, including those in the NNIN and/or REU summer program, are females or minorities. The group maintains good relationships with the faculties at these neighboring minority-serving schools and the PI regularly gives seminars there, while the Laser Dynamics Laboratory is on the Georgia Tech list of laboratories that are open to visiting groups of students and teachers from the local community.