LEAPS-MPS: Utilizing Interband Transitions in Metallic Nanoparticles for Photocatalysis

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。加州大学默塞德分校（University of California at Merced）的Son Nguyen教授和他的研究小组打算研究纳米尺寸的金属粒子如何吸收光子并加速化学反应。通过改变光子能量，观察相应的化学产物，并将粒子的光激发态与产物形成速率联系起来，研究人员试图揭示粒子的工作机制。这项工作的成功实施可能为未来化学合成中制备绿色材料提供一些基本规则。Nguyen小组打算通过提供纳米科学和可持续能源方面的专业准备和实践研究经验，帮助代表性不足的学生在STEM领域取得成功。这些培训活动非常适合加州大学默塞德分校的使命，包括为西班牙裔社区服务，支持第一代大学生和经济困难的学生。在这个项目中，Nguyen小组打算揭示带间跃迁诱导的催化机理，寻求金属纳米颗粒新的反应机理和潜在的应用，主要有两个目标：1)建立热孔对铃木偶联反应的催化机理和活性；2)扩大热孔对其他偶联反应的催化作用。介孔纳米粒子将用于解决等离子体共振和带间跃迁的光谱重叠问题。多孔纳米颗粒的等离子体共振从可见光区转移到近红外区，允许Nguyen小组在没有等离子体共振光谱干扰的情况下，在可见光区询问由带间跃迁引起的光催化。与非多孔纳米颗粒对应的对照实验，其中带间跃迁和等离子体共振在光谱上重叠，将允许Nguyen小组区分每种光激发机制的催化贡献。将研究几个模型反应，包括C-C和C-N偶联，以突出带间跃迁的催化作用和应用。该项目有可能刺激纳米材料光催化的研究，并加快光化学的实际应用。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Professor Son Nguyen and the research group at the University of California at Merced intend to investigate how metallic, nanometer size particles absorb photons and accelerate chemical reactions. Through varying photon energy, observing the corresponding chemical products, and correlating the photoexcited state of the particles to the rate of product formation, the researchers intend to reveal the working mechanism of the particles. Successful implementation of the proposed work may provide some fundamental rules for preparing green materials for future chemical synthesis. The Nguyen group intends to assist under-represented students succeed in STEM fields by providing professional preparation and hands-on research experience in nanoscience and sustainable energy. These training activities are well suited to the missions of the University of California at Merced, including serving the Hispanic community and supporting first-generation college and economically disadvantaged students. In this project, the Nguyen group intends to reveal the catalytic mechanism induced by interband transitions to seek a new reaction mechanism and potential application of metallic nanoparticles via two main goals: i) establishing the catalytic mechanism and activities of hot holes for Suzuki coupling reactions and ii) expanding the catalysis of hot holes for other coupling reactions. Mesoporous nanoparticles will be utilized to solve the challenging spectral overlap of plasmon resonance and interband transitions. The plasmon resonance of the porous nanoparticles is shifted from the visible to near infrared region, allowing the Nguyen group to interrogate the photocatalysis induced by interband transitions in the visible region without spectral interference of the plasmon resonance. Control experiments with non-porous nanoparticle counterparts, in which interband transitions and plasmon resonance are spectrally overlapped, will allow the Nguyen group to differentiate the catalytic contribution from each photoexcitation regime. Several model reactions, including C-C and C-N couplings, will be studied to highlight the catalytic role and application of interband transitions. This project has the potential to stimulate research in nanomaterial-based photocatalysis and expedite the application of photochemistry for practical use.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.