Reduced colloidal metal-oxide nanocrystals as novel redox reagents

James M.华盛顿大学的Mayer获得了大分子、超分子和纳米化学项目的合作研究奖，该项目旨在研究含有额外电子的胶体氧化物半导体纳米颗粒的化学反应性和物理性质。纯的和掺杂的ZnO和TiO 2纳米粒子的不同尺寸，带隙，并与不同的表面封端基团将进行研究。这些粒子的光激发，然后空穴捕获产生稳定的解决方案，减少纳米粒子，含有电子的导带轨道或“陷阱状态”。合成，分析和光谱技术将被整合，以发展管理这些纳米粒子的反应性的结构/功能关系的基本理解。将通过跟踪空穴捕获后形成的有机产物和质子，并通过光激发纳米粒子的光谱演化来检查纳米粒子充电化学。将使用分子和微电子基底检查还原颗粒执行多电子/多质子反应的能力。将检查掺杂和表面改性的影响。减少粒子的光谱，热化学和动力学性质之间的连接将被开发。这项研究将产生新的基础科学见解，可能会改变这些材料的理解方式，并应用于各种技术，包括光电化学电池或电池的氧化物/溶液界面。这项研究将解决金属氧化物纳米结构的基本反应性。这种纳米结构在能量转换、能量存储和生物技术中无处不在，从拟议的研究中收集到的信息将对这些技术中的每一项技术产生广泛的影响。该项目还可能导致开发廉价，耐用，环保的多电子还原试剂，具有可调的潜力，可应用于从基础研究到催化的各种科学背景。最后，这项研究将为一般电子转移化学提供新的基本见解，并加深我们对这类重要反应的理解。除了产生新的基础科学见解和新材料外，这项研究还将为本科生和研究生提供先进的跨学科教育和培训机会，为他们未来的科学和工程职业做好准备。重点将放在研究和教育的一体化，在本科层次通过本科生参与研究，实验和概念的研究纳入本科实验室课程，与教师和本科院校的学生合作，并在区域社区学院和高中的推广活动。

James M. Mayer of the University of Washington is supported by an award from the Macromolecular, Supramolecular and Nanochemistry Program in collaborative research that seeks to examine the chemical reactivities and physical properties of colloidal oxide semiconductor nanoparticles containing extra electrons. Pure and doped ZnO and TiO2 nanoparticles of different sizes, band gaps, and with different surface-capping groups will be studied. Photoexcitation of these particles followed by hole trapping yields stable solutions of reduced nanoparticles, containing electrons in conduction-band orbitals or in "trap states". Synthetic, analytical, and spectroscopic techniques will be integrated to develop a fundamental understanding of the structure/function relationships that govern the reactivities of these nanoparticles. The nanoparticle charging chemistries will be examined by tracking the organic products and protons that are formed upon hole trapping, and by following the evolution of the photoexcited nanoparticles spectroscopically. The ability of the reduced particles to perform multi-electron/multi-proton reactions will be examined using molecular and nanocrystal substrates. The influence of nanocrystal doping and surface modification will be examined. Connections among the spectroscopic, thermochemical, and kinetic properties of the reduced particles will be developed. This research will yield new fundamental scientific insights that could alter the ways such materials are understood and applied in various technologies including the oxide/solution interfaces of photoelectrochemical cells or batteries.This research will address fundamental reactivities of metal-oxide nanostructures. Such nanostructures are ubiquitous in energy conversion, energy storage, and photocatalysis technologies, and the information gleaned from the proposed research will have broad implications in each of these technologies. This project could furthermore result in the development of inexpensive, robust, and environmentally sound multi-electron reducing reagents with tunable potentials for application in a variety of scientific contexts from fundamental research to catalysis. Finally, this research will provide new fundamental insights into general electron transfer chemistries and will deepen our understanding of this important class of reactions. In addition to yielding new fundamental scientific insights and new materials, this research will also provide undergraduate and graduate students with opportunities for advanced interdisciplinary education and training to prepare them for future careers in science and engineering. Emphasis will be placed on integration of research and education at the undergraduate level through involvement of undergraduates in the research, incorporation of experiments and concepts from the research into the undergraduate laboratory curriculum, collaboration with faculty and students from undergraduate institutions, and outreach activities at regional community colleges and high schools.