Near-field coupling between molecular vibrations and plasmonic metal oxide nanocrystals

化学家可以培育出极小的晶体。最小的晶体可能只有几纳米大小，或者比一张纸小10万倍。 这些小晶体只含有几千个原子。一些纳米晶体可以聚集光，聚集的能量可以用于从太阳能转换到传感的应用。 然而，单一类型的聚光灯只能集中几种颜色的光。通过改变其化学成分，可以针对特定应用调整这种颜色。 在化学系的大分子、超分子和纳米化学项目的支持下，德克萨斯大学奥斯汀分校的迪利亚·米利龙教授正在培育能聚集红外光的纳米晶体。虽然我们看不见红外光，但我们能感觉到它是来自阳光或热火的热量。与她的学生合作，Milliron教授正在研究一个晶体的大小、形状和组成如何影响其聚集红外光的能力。他们的发现可能会导致更好的方法来检测特定的化学品和改进催化方法，这将对社会产生重大利益。 一个关于纳米科学和光物质相互作用的互动教育模块正在进行调整，以接触不同的受众，包括德克萨斯州聋人学校的高中生和访问UT校园参加女孩节和探索UT的年轻学生，这两个项目都是面向社区的外展活动。该项目的目标是合成开发胶体金属氧化物纳米晶体（NC）含有异价掺杂剂，其诱导高浓度的自由电子，导致中红外光谱区域中的局部表面等离子体共振（LSPR）。定量地研究了LSPR模式与邻近有机分子振动模式之间的耦合。大多数关于LSPR的研究都集中在贵金属上，这些贵金属必须被图案化成更大的微米级金属结构才能达到中红外频率。该方法的局限性激发了对等离子体金属氧化物NCs的研究。这是定量地建立NC理化性质如何控制LSPR和振动模式之间耦合的性质和强度，最终导致开发灵敏和化学特异性检测器所需的基本理解，并指导能量流动以调节和增强催化过程。该团队正在创建互动教育活动，展示光和物质的相互作用如何用于现代应用，如电子显示器和太阳能电池。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Chemists can grow extremely small crystals. The smallest crystals can be only a few nanometers in size, or about 100,000 times smaller than a sheet of paper. These small crystals contain just a few thousand atoms. Some nanocrystals can concentrate light and the focused energy can be used in applications ranging from solar energy conversion to sensing. However, a single type of nanocrystal can only concentrate a few colors of light. By changing its chemical composition, one can adjust this color for specific applications. With support from the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Professor Delia Milliron at the University of Texas at Austin is growing nanocrystals that concentrate infrared light. While we cannot see infrared light, we feel it as heat from sunlight or a hot fire. Working with her students, Professor Milliron is studying how the size, shape, and composition of a nanocrystal influences its ability to concentrate infrared light. Their discoveries could lead to better ways of detecting specific chemicals and improved catalytic methods, which would have important benefits to society. An interactive educational module regarding nanoscience and light-matter interactions is being adapted to reach diverse audiences, including high school students at Texas School for the Deaf and younger students who visit UT's campus for Girl Day and Explore UT, both are community-oriented outreach events.This project targets the synthetic development of colloidal metal oxide nanocrystals (NCs) containing aliovalent dopants that induce a high concentration of free electrons, leading to localized surface plasmon resonance (LSPR) in the mid-infrared spectral region. Coupling between LSPR modes and the vibrational modes of proximal organic molecules is studied quantitatively. Most research on LSPR has focused on noble metals, which must be patterned into larger, micron-scale metal structures to reach mid-infrared frequencies. The limitations of that approach motivate the investigation of plasmonic metal oxide NCs. This is quantitatively establishing how NC physiochemical properties control the nature and strength of coupling between LSPR and vibrational modes, ultimately leading to the foundational understanding needed to develop sensitive and chemically specific detectors, and to direct the flow of energy to tune and enhance catalytic processes. The team is creating interactive educational activities that illustrate how the interaction of light and matter is used in modern applications, such as electronic displays and solar cells.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.