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Establishing a Chemical Toolbox for Programmed Assembly of Metal Chalcogenide Nanoparticles into "Wired" Architectures

建立化学工具箱，用于将金属硫族化物纳米粒子编程组装成“有线”结构

基本信息

批准号：
1709776
负责人：
Stephanie Brock
金额：
$ 31万
依托单位：
Wayne State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2020-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709776&HistoricalAwards=false
关键词：
Establishing Chemical Toolbox Programmed Assembly

项目摘要

Energy is all around us, but much of it is not very useful. Scientists are interested in ways to take wasted energy, and convert it into useful energy supplies. Dr. Stephanie Brock is investigating how to convert plentiful solar energy into electricity or chemical fuels. She is particularly interested in the challenging problem of how to harvest "light". Quantum dots are very small particles that have dimensions on the order of 1/1000th of a red blood cell and are great at absorbing solar radiation and producing charged particles. Accordingly, Dr. Brock is developing techniques that enable these sub-microscopic quantum dot particles to be assembled into films and 3 dimensional porous structures with millimeter to centimeter dimensions. Dr. Brock is developing methods that enable quantum dots with different chemical potentials to attach to each other, thereby creating a voltage difference that can move an electrical current within the structure. She is also working to understand how the chemical nature of the inter-particle bonding affects the ability to rapidly move the charges, and how these charges can sometimes get "trapped" and resist extraction. This fundamental knowledge helps in the design of efficient solar cells and photochemical water-splitting (hydrogen fuel generation) systems. Dr. Brock's research is attractive to graduate and undergraduate students alike, who are exposed to cutting-edge science through participation in her lab. Dr. Brock is also developing science modules aimed at middle-to-high school students to give them hands-on experiences in the lab. She is implementing these through the Wayne State University's GO-GIRLs outreach program. In this research program, Dr. Stephanie Brock of Wayne State University is supported by the Macromolecular, Supramolecular and Nanochemistry (MSN) Program to develop a chemical toolbox to (1) enable the rate of assembly of different metal chalcogenide nanoparticle components to be varied. This ability may dictate the degree of phase-segregation in multicomponent systems; (2) provide post- and pre-assembly chemical modifications of the interfaces to facilitate electron transport. The kinetic parameters dictating oxidative assembly of nanoparticles (made of MQ where M = cadmium, lead, zinc; Q = sulfur, selenium, tellurium) are studied as a function of the redox properties of Q, the solubility of M, the crystal structure of MQ, the facet energetics and the surface ligand group. In parallel, methods for replacement of oxidized interfaces with metal-ion crosslinks by post-gelation oxidative addition reactions or (pre-gelation) assembly of sulfide or halide-capped nanoparticles via metal cations, are evaluated. The ability to control the rate of solution-phase assembly of metal chalcogenide nanoparticles, thereby enabling programmable assembly of disparate nanoparticle components into 2- and 3-D "wired" architectures with specified degrees of heterogeneity, enable design of multicomponent assemblies for applications that benefit from rapid injection of charges over short distances (e.g., photocatalysts prepared from homogeneous assembly of photosensitizer + catalyst) or require extraction over large distances (e.g., bulk nanoheterojunction solar cells comprising p + n semiconductors). Chemical principles are also employed to tune the nature of the interparticle interfaces, thereby augmenting interparticle transport and the overall stability of the assembly. Dr. Brock involves graduate and undergraduate students in interdisciplinary collaborative research and modern characterization techniques. She introduces Detroit-area adolescent girls, many of whom are minorities, to chemistry through the GO-GIRLs outreach program.

能源就在我们身边，但其中大部分都不是很有用。科学家们对如何将浪费的能源转化为有用的能源很感兴趣。Stephanie Brock博士正在研究如何将丰富的太阳能转化为电力或化学燃料。她对如何收获“光”这个具有挑战性的问题特别感兴趣。量子点是非常小的粒子，其尺寸约为红细胞的千分之一，并且非常善于吸收太阳辐射并产生带电粒子。因此，Brock博士正在开发技术，使这些亚微观量子点颗粒能够组装成毫米到厘米尺寸的薄膜和三维多孔结构。 Brock博士正在开发一种方法，使具有不同化学势的量子点相互附着，从而产生一个电压差，可以在结构内移动电流。她还致力于了解粒子间结合的化学性质如何影响快速移动电荷的能力，以及这些电荷有时如何被“捕获”并抵抗提取。这些基础知识有助于设计高效的太阳能电池和光化学水分解（氢燃料发电）系统。布洛克博士的研究对研究生和本科生都很有吸引力，他们通过参与她的实验室接触到了前沿科学。布洛克博士还开发了针对初中到高中学生的科学模块，让他们在实验室中获得实践经验。她正在通过韦恩州立大学的GO-GIRL外展计划实施这些计划。在这项研究计划中，韦恩州立大学的Stephanie Brock博士得到了大分子、超分子和纳米化学（MSN）计划的支持，开发了一个化学工具箱，以（1）使不同金属硫属化物纳米颗粒组分的组装速率不同。这种能力可以决定多组分体系中的相分离程度;（2）提供组装后和组装前的界面化学改性，以促进电子传输。的动力学参数支配的氧化组装的纳米粒子（MQ，其中M =镉，铅，锌; Q =硫，硒，碲）的氧化还原性质的Q，M的溶解度，MQ的晶体结构，方面的能量和表面配体基团的函数进行了研究。同时，评价了通过凝胶化后氧化加成反应或（凝胶化前）硫化物或卤化物封端的纳米颗粒通过金属阳离子的组装来用金属离子交联替换氧化界面的方法。控制金属硫属化物纳米颗粒的溶液相组装速率的能力，从而使得能够将不同的纳米颗粒组分可编程地组装成具有指定程度的异质性的2-和3-D“有线”架构，使得能够设计用于受益于短距离内快速注入电荷的应用的多组分组装件（例如，由光敏剂+催化剂的均匀组合体制备的光催化剂）或需要长距离提取（例如，包括p + n半导体的体纳米异质结太阳能电池）。化学原理也被用来调整粒子间界面的性质，从而增强粒子间的传输和组装的整体稳定性。布洛克涉及研究生和本科生在跨学科的合作研究和现代表征技术。她介绍底特律地区的少女，其中许多是少数民族，化学通过GO-GIRL外展计划。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Effect of metal ion solubility on the oxidative assembly of metal sulfide quantum dots

金属离子溶解度对金属硫化物量子点氧化组装的影响

DOI：
10.1063/1.5128932
发表时间：
2019
期刊：
The Journal of Chemical Physics
影响因子：
0
作者：
Silva, Karunamuni L.;Silmi, Leenah;Brock, Stephanie L.
通讯作者：
Brock, Stephanie L.

Application of Aqueous-Based Covalent Crosslinking Strategies to the Formation of Metal Chalcogenide Gels and Aerogels

DOI：
10.1515/zpch-2018-1171
发表时间：
2018-08-01
期刊：
ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS
影响因子：
2.5
作者：
Hewavitharana, Indika K.;Brock, Stephanie L.
通讯作者：
Brock, Stephanie L.

Electrochemical gelation of quantum dots using non-noble metal electrodes at high oxidation potentials