Continuous Manufacturing of Anhydrous Metal Sulfide Nanocrystals

金属硫化物纳米晶体以其优异的性能在润滑、光电子、催化、生物技术、储能等领域得到了广泛的应用。纳米晶体的反应性沉淀通常是通过将水溶液结合形成过饱和混合物来完成的。这种工艺对加工条件很敏感，使得无水相纯材料的合成具有挑战性，一般来说，对湿敏合金来说是不可能的。该奖项支持通过硫化氢气体与有机金属前体在有机溶液中的反应制造无水金属硫化物纳米颗粒的研究。该项目解决了将这种基于解决方案的方法转化为可扩展的纳米制造工艺所涉及的工程挑战。开发了一种气泡塔反应器平台，用于反应沉淀法连续制备纳米晶体。该项目针对下一代电池技术面临的重要材料挑战。这种制造能力对于广泛部署可再生风能和太阳能发电至关重要，这将极大地影响国家的繁荣和基础设施。该项目为能源技术领域的本科生和研究生工程师和科学家提供跨学科培训。项目成果被纳入本科课程。气泡柱平台的构建与实现是单元操作实验课程中的一个模块。该项目提出了一种绿色化学方法，可以完全减少有害工业废气硫化氢，同时生成金属硫化氢纳米晶体并回收有价值的氢。该项目旨在提取气泡塔反应性沉淀过程设计和操作的一般原则，包括四阶段设计。该研究包括通过合理选择化学物质（溶剂、辅助试剂）和系统地操纵质量传递参数来控制金属硫化物纳米颗粒的大小和形态的能力。研究了半间歇操作下的纳米颗粒合成，指导了连续制造平台的设计和实现。通过原型阴极和固态电解质的制作和评价，表征了纳米颗粒的结构、性能和性能。连续生产有望改善对纳米晶体形状和尺寸分布的控制，这对这些材料的应用至关重要。气相反应物与有机溶液的结合为水敏纳米颗粒的反应性沉淀提供了一种新的范例。该奖项反映了美国国家科学基金会的法定使命，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。

Metal sulfide nanocrystals have attracted great attention because of their excellent properties and widespread applications in diverse fields including lubrication, optoelectronics, catalysis, biotechnology, and energy storage. Reactive precipitation of nanocrystals is typically accomplished by combining aqueous solutions to create supersaturated mixtures. Such processes are sensitive to processing conditions making the synthesis of anhydrous phase pure materials challenging, in general, and impossible for moisture sensitive alloys. This award supports the study of the manufacture of anhydrous metal sulfide nanoparticles through the reaction of hydrogen sulfide gas with metal-organic precursors in an organic solution. The project addresses the engineering challenges involved in translating this solution-based approach into a scalable nanomanufacturing process. It develops a bubble column reactor platform for continuous manufacturing of the nanocrystals via reactive precipitation. The project targets important materials challenges facing next generation battery technologies. Such a manufacturing capability is critical for enabling widespread deployment of renewable wind- and solar-generated electricity, which greatly impacts the nation's prosperity and infrastructure. This project provides interdisciplinary training for undergraduate and graduate engineers and scientists in energy technology areas. Project results are integrated into the undergraduate curriculum. The building and implementation of the bubble-column platform serves as a module in a unit operations laboratory course.This project advances a green chemistry approach that results in complete reduction of the hazardous industrial waste gas hydrogen sulfide while generating metal sulfide nanocrystals and recovering valuable hydrogen. The project aims to extract general principles for the design and operation of reactive precipitation processes in bubble columns, including a four-phase design. The research involves demonstrating the ability to control the size and morphology of metal sulfide nanoparticles through rational selection of chemistry (solvent, auxiliary reagent) and systematic manipulation of mass transport parameters. Studies of nanoparticle synthesis under semi-batch operation are used to guide the design and implementation of a continuous manufacturing platform. The structure, properties and performance of the nanoparticles are characterized through the fabrication and evaluation of prototype cathodes and solid-state electrolytes. Continuous production is expected to improve control over nanocrystal shape and size distribution that is critical in the applications of these materials. The combination of gas-phase reactants with organic solutions offers a new paradigm for the reactive precipitation of moisture sensitive nanoparticles.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.