Synthesis and Detailed Chemical Structure of Isotopically Enriched Graphite Oxide, Reduce Graphene Oxides, and Chemically Modified Graphenes

同位素富集氧化石墨、还原氧化石墨烯和化学改性石墨烯的合成和详细化学结构

• 批准号: 1206986
• 负责人: Rodney Ruoff
• 金额: $ 39.5万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206986&HistoricalAwards=false
• 关键词: Synthesis; Detailed; Chemical; Structure; Isotopically

TECHNICAL SUMMARYA novel technique for growing synthetic graphite from methane on resistively-heated metal foils has been developed. This method allows the control of the thickness and, crucially, the isotopic composition of the graphite. Three research paths will be pursued in this program funded by the Solid State and Materials Chemistry Program. Formation mechanisms and structures of reduced graphene oxides and other chemically modified graphenes (CMGs): With the ratio of 13C/12C as a variable, synthetic graphite will be converted to graphite oxide (GO). Both as-produced and exfoliated GO will be subjected to various modifications such as chemical, physical, or biological reduction, or functionalization, to give CMG materials. This 13C-enriched GO will be a fascinating carbon source to study the detailed molecular structure and the formation mechanism of the new type of carbon that has been recently discovered in our lab (KOH activated microwaved exfoliated graphite oxide called 'a-MEGO') (Science 2011). The fundamental study on the change of the local or global electronic structure and the Density of States (DOS) of CMG by foreign atoms (such as N, B, etc) is made both experimentally and theoretically possible with the aid of 13C-labeled carbon sources. This a-MEGO material will be extensively characterized by solid-state NMR (SS-NMR), imaging micro-Raman, Fourier transform infra-red (FT-IR) spectroscopy, and other techniques to determine the molecular structure of these CMGs. The CMGs will be characterized to determine their chemical structures and the molecular-level mechanisms at work during their production. This information will be used to optimize the chemistry of CMG production for important uses, e.g., the synthesis of conductive material for electrical energy storage. Improved growth of 13C-enriched material: We will continue to study our growth methods to further the quality, quantity, and forms of 13C-enriched carbons that we can produce. For example, a new type of growth system (RF heating/UHV components) has been built, that should offer significant advantages compared to our existing setup. This new system should result in extra material that we can supply to potential collaborators. Growth of graphite as a source of thin graphene films: It is possible to produce layers of graphite only a few sheets thick, with lateral dimensions of many microns. Improved methods of removing the graphite from the substrate to produce high-quality graphene that can also be 13C-enriched for fundamental physical studies will be developed.NON-TECHNICAL SUMMARYThe goal of this proposed research is to better understand the structure of materials derived from the chemical modification of graphite. To do this, the materials must be made from synthetic graphite enriched in the 13C isotope of carbon. The methods that are established for 13C-enriched graphite production will mean that this new material type will be broadly available for studies by other scientists. Improved understanding of the chemistries of graphite oxide and derivatives will be important for the development of materials based on chemically modified graphite. These materials may find application in diverse areas such as: energy storage materials and in structural materials. The proposal includes a significant program in outreach, such as: research programs for graduate students and postdoctoral fellows; continuous and summer research training for high school and undergraduate (including minority) students and high school teachers; additions to course materials; and curriculum development for grades 7-12 by teacher training through the UTeach program at the University of Texas at Austin. There are ongoing collaborations with Oak Ridge National Laboratory and with colleagues at the University of Illinois-Chicago (SS-NMR).

研究了一种在电阻加热金属箔上以甲烷为原料生长合成石墨的新技术。这种方法可以控制石墨的厚度，更重要的是，还可以控制石墨的同位素组成。该项目由固态与材料化学项目资助，将有三条研究路径。还原氧化石墨烯和其他化学修饰石墨烯（cmg）的形成机理和结构：以13C/12C的比值为变量，合成石墨将转化为氧化石墨（GO）。生产的和去角质的氧化石墨烯都将经过各种修饰，如化学、物理或生物还原或功能化，以获得CMG材料。这种富含13c的氧化石墨烯将是研究我们实验室最近发现的新型碳的详细分子结构和形成机制的一个迷人的碳源（KOH活化微波剥离氧化石墨称为“a- mego”）（Science 2011）。借助13c标记的碳源，可以从实验和理论上研究外源原子（如N、B等）对CMG的局域或全局电子结构和态密度（DOS）的变化。这种a-MEGO材料将通过固态核磁共振（SS-NMR）、成像微拉曼、傅里叶变换红外（FT-IR）光谱和其他技术进行广泛表征，以确定这些cmg的分子结构。将对CMGs进行表征，以确定其化学结构和在其生产过程中起作用的分子水平机制。这些信息将用于优化CMG生产的化学过程，用于重要用途，例如，用于电能存储的导电材料的合成。提高富含13c的材料的生长：我们将继续研究我们的生长方法，以进一步提高我们可以生产的富含13c的碳的质量、数量和形式。例如，一种新型的生长系统（射频加热/特高压组件）已经建成，与我们现有的设置相比，它应该具有显着的优势。这个新系统会产生额外的材料，我们可以提供给潜在的合作者。作为石墨烯薄膜来源的石墨的生长：有可能生产几层厚度的石墨层，其横向尺寸为许多微米。将开发从衬底上去除石墨以生产高质量石墨烯的改进方法，这种石墨烯也可以富含13c，用于基础物理研究。本研究的目的是为了更好地了解石墨化学改性材料的结构。要做到这一点，材料必须由富含碳的13C同位素的合成石墨制成。为生产富含13c的石墨而建立的方法将意味着这种新材料类型将广泛用于其他科学家的研究。提高对氧化石墨及其衍生物的化学性质的了解对于开发基于化学改性石墨的材料将是重要的。这些材料可以应用于多种领域，如：储能材料和结构材料。该提案包括一个重要的外展项目，例如：研究生和博士后的研究项目；高中和本科（包括少数民族）学生和高中教师的持续和暑期研究培训；课程材料的补充；通过德克萨斯大学奥斯汀分校的UTeach项目对教师进行培训，开发7-12年级的课程。与橡树岭国家实验室和伊利诺伊大学芝加哥分校（SS-NMR）的同事正在进行合作。