CAREER: Hybrid Bronzes: Mixed-Valence Hybrid Metal Oxides as a Tunable Material Platform

职业：混合青铜：混合价混合金属氧化物作为可调材料平台

• 批准号: 2338086
• 负责人: Adam Jaffe
• 金额: $ 79.75万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2029-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2338086&HistoricalAwards=false
• 关键词: CAREER; Hybrid; Bronzes; Mixed; Valence

PART 1: Non-Technical SummaryRenewable energy technologies such as solar cells, batteries, and fuel cells are critical for addressing urgent global energy demand in a sustainable manner. These systems rely on materials that are highly stable and, as a function of their ordered structures, display important properties for energy-related use such as efficient light absorption and the ability to easily conduct electrical current. However, it is challenging and costly to synthesize and modify important crystalline solids such as metal oxides. The chemical tuning of molecules, on the other hand, is more precise and less energy intensive. With this CAREER award, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, the principal investigator and his research group investigate how to combine the best qualities of molecules and materials by developing design principles for an emerging new class of organic-inorganic materials called hybrid bronzes. These easily synthesized, low-cost, and air-/water-stable compounds achieve atomic-level integration of metal oxide layers with molecules having adjustable functions, thereby providing a tunable material platform that can cater to numerous desired applications. This work elucidates structure-property relationships governing the electronic behavior of hybrid bronzes to inform their ultimate implementation in energy-related technologies. Furthermore, this interdisciplinary research program trains undergraduate and graduate students as the diverse future STEM workforce and develops a multi-faceted instructional video platform called "Lab Hacks" that seeks to lower resource and knowledge barriers in STEM education and research.PART 2: Technical SummaryHybrid bronzes are bulk crystalline materials that combine alternating layers of (1) mixed-valence metal oxide sheets featuring tunable charge-carrier densities and band gaps and (2) molecular arrays with the potential for chemical-, redox-, and photo-activity. Here, the term "bronze" refers to the metallic luster that quasi-free electrons impart to reduced metal oxides and it is these mobile carriers that ultimately enable such electronic versatility. To advance the hybrid bronze platform toward energy-related use, it is necessary to understand and subsequently control their redox activity, light absorption, and charge transport. Hybrid bronzes also represent versatile model systems that can probe questions regarding two-dimensional solid-state phenomena. With this CAREER award, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, the principal investigator and his research group leverage mild aqueous self-assembly reactions to produce bulk crystalline hybrid bronzes with a fine degree of synthetic control. A suite of diffraction-based, spectroscopic, and electronic characterization techniques including high-pressure methods are then employed to elucidate structure-property relationships. Specifically, evaluation of systematically varied molecular structure-directing effects illuminates how charge transport is dictated within inorganic layers. Principles governing stimulus-driven charge transfer phenomena between molecules and layers are explored through optoelectronic, electrochemical, and charge transport analysis, followed by iterative molecular tuning. Further, pressure/strain-induced structure changes are employed as a unique approach to dictating electronic property transitions within hybrid bronzes. Overall, this work reveals connections between the structures and electronic behaviors of hybrid bronzes, including emergent phenomena, to demonstrate design rules enabling their customization.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第 1 部分：非技术摘要太阳能电池、电池和燃料电池等可再生能源技术对于以可持续方式满足全球紧迫的能源需求至关重要，这些系统依赖于高度稳定且具有有序结构的材料。 ，显示出与能源相关的用途的重要特性，例如有效的光吸收和轻松传导电流的能力，然而，合成和修饰重要的结晶固体（例如金属氧化物）具有挑战性且成本高昂。另一方面，更精确且在美国国家科学基金会材料研究部的固态和材料化学项目的支持下，首席研究员和他的研究小组如何通过开发新兴的新设计原理来结合分子和材料的最佳品质。这些易于合成、低成本且空气/水稳定的有机-无机材料可实现金属氧化物层与具有可调节功能的分子的原子级集成，从而提供可调节的材料平台。这项工作阐明了控制混合青铜电子行为的结构-性能关系，为它们在能源相关技术中的最终实现提供信息。此外，这个跨学科研究项目将本科生和研究生培养为多样化的未来 STEM 劳动力并发展。一个名为“Lab Hacks”的多方面教学视频平台，旨在降低 STEM 教育和研究中的资源和知识障碍。第 2 部分：技术摘要混合青铜是块状晶体材料，结合了 (1) 的交替层具有可调节电荷载流子密度和带隙的混合价金属氧化物片，以及（2）具有化学、氧化还原和光活性潜力的分子阵列这里，术语“青铜”指的是准金属光泽。 -自由电子传递给还原的金属氧化物，正是这些移动载体最终实现了这种电子多功能性，为了将混合青铜平台推向与能源相关的用途，有必要了解并随后控制它们的氧化还原活性、光吸收、混合青铜还代表了可以探索有关二维固态现象问题的多功能模型系统，该奖项得到了美国国家科学基金会材料研究部固态和材料化学项目的支持。研究小组利用温和的水自组装反应来生产块状晶体杂化青铜，并采用一套基于衍射、光谱和电子表征技术（包括高压方法）进行精细的合成控制。阐明结构-性质关系。对系统变化的分子结构导向效应的评估阐明了无机层内电荷传输是如何决定的，通过光电、电化学和电荷传输分析探索了控制分子和层之间刺激特定驱动的电荷转移现象的原理。 ，然后进行迭代分子调节。此外，采用压力/应变引起的结构变化作为指示混合青铜内电子性能转变的独特方法。总体而言，这项工作揭示了混合青铜的结构和电子行为之间的联系。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。