Hierarchical Metal-organic Framework Assemblies for Solar Energy Harvesting and Storage

技术总结在材料研究部固态和材料化学计划的支持下，该项目将研究金属-有机骨架(MOF)作为模型材料系统，以分级集成功能分子和纳米粒子组件，用于太阳能收集和存储。太阳能收集为满足我们未来的能源需求提供了一个长期的解决方案。将太阳能转换为化学能需要材料系统同时执行三个基本步骤：天线吸收阳光以产生电荷分离的激发态，产生氧化还原当量并向反应中心进行矢量迁移，以及催化反应利用矢量传输的电子和空穴在产品中储存化学能。研究小组将开发合成方法，将所有关键功能部件分级集成到同一系统中，以发现太阳能收集和存储的新策略。他们将通过使用磷光桥联配体合成稳定的多孔光敏化MOF，在MOF中加入水氧化催化剂(WOCs)来驱动光催化水氧化生成二氧化氧，在MOF中加入质子还原催化剂(PRCs)来驱动光催化水还原生成H2，并将光敏剂(PS)、WOC和PRC整合到同一MOF体系中，实现光分解水和阳光。他们的研究工作有可能为光敏化、电荷注入和水氧化/质子还原反应提供基础知识。拟议的研究活动还将纳入博士后、研究生、本科生和高中生的培训。能源的可持续生产是人类最大的科学挑战之一。随着化石燃料供应的减少，必须开发新的能源技术，以满足日益增长的全球能源需求和维持全球社会的发展。太阳能是少数几种可以扩大规模以满足我们未来需求的替代能源之一。太阳能可以转化为热能、电能或燃料。其中，太阳能燃料最受欢迎，因为它们便于储存和运输。然而，用于超大规模太阳能燃料生产的实用和具有成本效益的技术目前尚不存在，需要在基础科学方面取得突破。研究小组将使用金属-有机骨架(MOF)作为模型材料系统，分层集成功能分子和纳米颗粒组件，用于太阳能收集和存储。拟议的研究活动不仅将使人们更好地了解太阳能转换中涉及的三个基本过程，包括光敏化、电荷注入和水氧化/质子还原反应，而且还有望导致用于太阳能收集和储存的新的和更好的材料系统。该项目将涉及来自所有人口统计学的学生，并将教授与现实世界需求相关的技能和技术，从而帮助为未来的清洁技术培养一支高技能的劳动力队伍。

TECHNICAL SUMMARYWith support from the Solid State and Materials Chemistry program in the Division of Materials research, this project will study metal-organic frameworks (MOFs) as a model material system to hierarchically integrate functional molecular and nanoparticle components for solar energy harvesting and storage. Solar energy harvesting provides a long-term solution to meet our future energy needs. Converting solar energy to chemical energy requires a material system to simultaneously perform three fundamental steps: sunlight absorption by antennae to create charge-separated excited states, creation of redox equivalents and their vectorial migration to reactive centers, and catalytic reactions to store chemical energy in the products using vectorially delivered electrons and holes. The research team will develop synthetic methods to hierarchically integrate all of the key functional components into the same system in order to uncover new strategies for solar energy harvesting and storage. They will accomplish these objectives by synthesizing stable and porous photosensitizing MOFs using phosphorescent bridging ligands, incorporating water oxidation catalysts (WOCs) into MOFs to drive photocatalytic water oxidation to generate dioxygen; incorporating proton reduction catalysts (PRCs) into MOFs to drive photocatalytic water reduction to produce H2, and integrating the photosensitizer (PS), WOC, and PRC into the same MOF system to achieve total water splitting with sunlight. Their research efforts have the potential to provide fundamental understanding of photosensitization, charge injection, and water oxidation/proton reduction reactions. The proposed research activities will also be integrated into the training of postdoctoral, graduate, undergraduates, and high school students. NON-TECHNICAL SUMMARYThe sustainable production of energy is one of humanity's greatest scientific challenges. As the fossil fuel supply dwindles, new energy technologies must be developed to meet the increasing global energy needs and to sustain the global society. Solar energy is one of the few alternative energy sources that could be scaled up to meet our future needs. Solar energy can be converted into heat, electricity, or fuels. Among them, solar fuels are the most desirable because of the ease of their storage and transportation. However, practical and cost-effective technologies for ultralarge-scale solar fuel production do not currently exist and require breakthroughs in basic sciences. The research team will use metal-organic frameworks (MOFs) as a model material system to hierarchically integrate functional molecular and nanoparticle components for solar energy harvesting and storage. The proposed research activities will not only provide better understanding of the three fundamental processes involved in solar energy conversion, including photosensitization, charge injection, and water oxidation/proton reduction reactions, but also promise to lead to new and better material systems for solar energy harvesting and storage. The project will involve students from all demographics and will teach skills and techniques that are relevant to real-world needs, thus helping prepare a highly skilled workforce for future clean technology.