Collaborative Research: Thermochemistry and Chemical Kinetics of Halide-driven Crystal Structure Control of Manganese and Lanthanide Chalcogenide Nanocrystals

合作研究：卤化物驱动的锰和镧系硫族化物纳米晶体晶体结构控制的热化学和化学动力学

• 批准号: 2305153
• 负责人: Emil Hernández-Pagán
• 金额: $ 41.47万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305153&HistoricalAwards=false
• 关键词: Collaborative; Research; Thermochemistry; Chemical; Kinetics

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Drs. Emil Hernández-Pagán of the University of Delaware, Kristina Lilova of Arizona State University, and Robert Wexler of Washington University in St. Louis will investigate how the presence of halides (chloride, bromide, and iodide) influences the final arrangements of atoms (crystal structure) in the synthesis of certain classes of nanoparticles. The team will employ experimental techniques, including ones that provide information as the reaction occurs, and computational methods to gain in depth insight into this process. The particular crystal polymorph often dictates key properties of nanocrystalline materials and, consequently, the applications for which these can be used, for example, in photovoltaics, catalysis, and energy storage. Therefore, having the knowledge and ability to control the crystal structure is important. The broader impacts of this work are centered around (a) providing experimental and computational training to the students working on this project and (b) summer research experiences for undergraduate students from Puerto Rico that aim to complement the training they receive at their home institutions to better prepare them for the workforce and/or pursuing a graduate degree. The ability to rationally synthesize a given polymorph or phase of a nanoparticles is desirable as these dictate their mechanical, optical, and electronic properties. The proposed work synergistically combines experimental and computational methods to provide a holistic framework for a model system where halides drive the control of crystal structure/phase in the synthesis of manganese chalcogenide nanocrystals. This framework will encompass identifying pre-nucleation molecular species, performing thermochemical measurement of reaction and surface-ligand interactions, and monitoring the kinetics of nucleation and growth. A suite of in situ techniques will be employed to enable such measurements under the reaction conditions. Quantum-mechanics-based calculations will be used to identify atomic-scale interactions and the mechanisms that lead to the observed crystal structures/phases. These calculations will provide input for kinetic and thermodynamic models of nanocrystal nucleation and growth and, therefore, will produce multi-scale-based computational guidance for the controlled synthesis of metal chalcogenide nanocrystals. The studies will be extended to lanthanide chalcogenide nanocrystals, which have remained largely unexplored despite unique optical and magnetic properties. This work is anticipated to further increase the level of chemical understanding of the synthesis of Mn and Ln chalcogenide nanocrystals, and such insights have the potential to provide guidance to the scientific community for the synthesis of other classes of materials.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.

在化学划分部的大分子，超分子和纳米化学计划的支持下。特拉华大学，亚利桑那州立大学克里斯蒂娜·莉洛娃（Kristina Lilova）和圣路易斯华盛顿大学的罗伯特·韦克斯勒（Robert Wexler）的埃米尔·埃尔南德斯·帕根（EmilHernández-Pagán）将调查在某些阶级的合成中，将如何影响卤化物（氯化物，溴化物，溴化物和碘化物）如何影响原子（晶体结构）的最终安排。该团队将采用实验技术，包括在反应发生时提供信息的技术，以及可以深入了解此过程的计算方法。特定的晶体多晶型通常决定纳米晶体材料的关键特性，因此，可以使用这些材料的应用，例如在光伏，催化和储能中。因此，拥有控制晶体结构的知识和能力很重要。这项工作的更广泛影响是（a）为从事该项目的学生提供实验和计算培训，以及（b）来自波多黎各的本科生的夏季研究经验，旨在完成他们在家庭机构接受的培训，以更好地为劳动力做好准备和/或攻读研究生学位。希望合理合成给定的多晶型物或纳米颗粒相位的能力，因为这些能力决定了它们的机械，光学和电子特性。提出的工作协同结合了实验和计算方法，为模型系统提供了整体框架，其中Halides在合成的锰硫化剂纳米晶体中驱动了晶体结构/相的控制。该框架将包括识别核前分子物种，对反应和表面配体相互作用进行热化学测量以及监测核和生长的动力学。将采用一套原位技术来在反应条件下实现此类测量。基于量子力学的计算将用于识别原子尺度相互作用以及导致观察到的晶体结构/相的机制。这些计算将为纳米晶成核和生长的动力学和热力学模型提供输入，因此将产生基于多尺度的计算指南，以控制金属辣椒剂纳米晶体的控制合成。研究将扩展到灯笼硫化葡萄甲化合物纳米晶体，这些纳米晶体在很大程度上仍然是意外的所需的独特光学和磁性特性。预计这项工作将进一步提高对MN和LN硫元素纳米晶体合成的化学理解水平，并且此类见解具有为科学界提供其他类别材料的指导的潜力。该奖项反映了NSF的法定任务，并通过使用基金会的Merit和Broadial and Intfactial和Broadia and Imparia和广泛的评估来进行评估。