On Heavier Chalcogen (Se and Te) Interfacial Chemistry and Charge Transfer in Monolayer-Protected Metal Nanoparticles

单层保护金属纳米粒子中重硫族元素（Se 和 Te）界面化学和电荷转移

• 批准号: 1413429
• 负责人: YuYe Tong
• 金额: $ 49万
• 依托单位: Georgetown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1413429&HistoricalAwards=false
• 关键词: Heavier; Chalcogen; Se; Te; Interfacial

Metal nanoparticles are metal particles of very small (nanometer scale) dimensions. They possess novel chemical and physical properties that are very different from those of large particles or bulk metals. Dr. YuYe Tong of Georgetown University and Dr. Thomas Allison at the National Institute of Standards and Technology conduct research to gain a better understanding of the structural parameters that govern the properties of metal nanoparticles. The long-term goal is to harness the novel properties of nanoparticles for practical applications (such as electronic or optical devices, biomedical diagnosis, and drug delivery). This project provides interdisciplinary research opportunities to students, training them in the use of the state-of-the-art instruments for studying nanoparticles. Through Georgetown University's partnership with the Cesar Chavez Public Charter Schools in Southeast Washington DC, which have very high population of students of underrepresented groups or from low-income families, Dr. Tong participates in a project to help develop new chemistry curricula for local charter schools. This project serves as a springboard to attract more women and underrepresented students to STEM fields.Dr. Tong and Dr. Allison explore the use of heavier chalcogen (Se and Te) as alternative anchoring elements to the prevailingly used sulfur for attaching organic molecular wires to metal surfaces. Using a combination of experimental techniques and Density Functional Theory (DFT) computations, they aim to gain a better mechanistic understanding of the metal-chalcogenolate interfacial chemistry and its ramifications on charge transfer/transport in single monolayer-protected nanoparticle (MPN) and MPN assemblies. Specifically, this research entails: 1) the synthesis of different sizes (1 to 5 nm) of nanoparticles of different metal elements (Au, Ag, Cu, Pt, and Pd), which are protected with ligands of different organic backbones (alkyl and aryl), alkyl chain lengths (C6, C8, and C12), and anchoring chalcogen elements (Se and Te); 2) the characterization of the afore-synthesized MPNs by in situ electrochemical (EC) spectroscopic (NMR/IR/Raman) techniques and ex situ X-ray photoemission spectroscopy; and 3) comparative mechanistic investigations of charge transfer through a single MPN and MPN assemblies using EC scanning tunneling microscopy and traditional EC measurements.

金属纳米颗粒是非常小（纳米尺度）尺寸的金属颗粒。它们具有与大颗粒或大块金属截然不同的化学和物理特性。乔治敦大学的童玉烨博士和美国国家标准与技术研究所的托马斯·艾利森博士进行研究，以更好地了解控制金属纳米颗粒特性的结构参数。长期目标是利用纳米颗粒的新特性进行实际应用（如电子或光学设备、生物医学诊断和药物输送）。该项目为学生提供跨学科的研究机会，训练他们使用最先进的仪器来研究纳米颗粒。乔治城大学与华盛顿特区东南部的塞萨尔·查韦斯公立特许学校（Cesar Chavez Public Charter Schools）合作，帮助当地特许学校开发新的化学课程。这些学校有很多来自弱势群体或低收入家庭的学生。该项目是吸引更多女性和代表性不足的学生进入STEM领域的跳板。Tong和Allison博士探索使用较重的硫（Se和Te）作为锚定元素，替代目前普遍使用的将有机分子线连接到金属表面的硫。利用实验技术和密度泛函数理论（DFT）计算的结合，他们旨在更好地理解金属-硫代酚酸酯界面化学及其对单层保护纳米粒子（MPN）和MPN组件中电荷转移/输运的影响。具体而言，本研究需要：1)合成不同尺寸（1 ~ 5nm）的不同金属元素（Au、Ag、Cu、Pt和Pd）纳米颗粒，这些纳米颗粒被不同有机骨架（烷基和芳基）、烷基链长（C6、C8和C12）和锚定的硫元素（Se和Te）的配体保护；2)利用原位电化学（EC）光谱（NMR/IR/Raman）技术和非原位x射线光电发射光谱对上述合成的mpn进行表征；3)利用电子扫描隧道显微镜和传统电子测量方法对单个MPN和MPN组件的电荷转移机制进行比较研究。