Energy funneling in plasmonic nanocrystal composites for photocatalytic production of solar fuels

用于太阳能燃料光催化生产的等离子体激元复合材料中的能量函数。Bowling绿色州立大学的Mikhail Zamkov博士正在开发一种新型的胶体纳米结构太阳能转换模型系统，旨在提高其光催化活性。所提出的纳米材料结构被设计成通过内置天线将太阳光汇集到复合纳米颗粒的中心。然后，吸收的辐射被引导到纳米颗粒的外部，以驱动其表面上的催化反应。为了实现有效的催化循环，采用了天线和催化剂之间的新型能量传递机制。所提出的创新利用复合纳米物体的无机域之间的明智设计的界面，以确保太阳能在光催化系统上的无缝传递。使催化纳米结构可溶，这允许将表面上的均相反应的益处（优异的活性和选择性）与多相系统的便利性相结合以再循环催化剂。这些材料特别适合于驱动水相反应，包括制氢和环境净化，在太阳光通量下具有增强的反应性。拟议的项目有助于研究人员在他的努力，继续在每年夏天从代表性不足的群体带来几个学生在实验室的全职研究实习。在这个由化学催化计划资助的项目中，来自Bowling绿色州立大学的Mikhail Zamkov博士专注于新型合成策略和超快光谱技术的协同作用，以探索利用复合胶体纳米结构的新型光催化材料。所提出的纳米材料联合收割机在一个单一的纳米反应器中结合了几个无机领域，设计用于有效地将太阳辐射转化为催化活性状态。纳米材料结构的关键创新在于等离子体辅助光捕获方案，该方案利用金属纳米颗粒中存在的强电磁场来促进周围半导体壳中激子的产生。然后，壳的激发能被传递到表面上的合适的氧化/还原催化剂。 为了确保复合纳米物体的不同成分无缝地工作，使用分子外延生长域间界面。这样的化学计量键（共价键或离子键）降低了耗散激发能的缺陷态的密度，使得能够实现吸收的辐射的高通量。研究人员的胶体纳米结构的催化性能使用常见的氧化还原反应在水介质中进行测试，而能量转移过程使用超快光谱技术进行研究。 作为建设俄亥俄州的可持续能源未来和科学，工程技术门户俄亥俄州计划的积极成员，教授扎姆科夫涉及本科生在这个研究项目的小团队，向他们介绍超快光谱，材料科学和化学合成的一般概念。特别努力让少数民族学生和代表性不足群体的学生参与进来。 Zamkov教授还与几个工业合作伙伴建立了联系，为本科研究人员提供工业实验室经验。

Energy funneling in plasmonic nanocrystal composites for photocatalytic production of solar fuels.Dr. Mikhail Zamkov of Bowling Green State University is developing a novel model system for solar energy conversion in colloidal nanostructures aimed toward improving their photocatalytic activity. The proposed nanomaterial architecture is designed to funnel the solar light into the center of a composite nanoparticle via a built-in antenna. The absorbed radiation is then routed toward the exterior of the nanoparticle to drive catalytic reactions on its surface. To enable an efficient catalytic cycle, a novel type of energy transfer mechanism between the antenna and the catalyst is employed. The proposed innovation makes use of judiciously engineered interfaces between inorganic domains of the composite nano-object to ensure a seamless transfer of the solar energy across the photocatalytic system. The catalytic nanostructures are rendered soluble, which allows combing the benefits of homogenous reactions on the surface (excellent activity and selectivity) with the facility of the heterogeneous systems to recycle the catalyst. These materials are particularly suited to drive aqueous phase reactions, including hydrogen production and environmental clean-up, with enhanced reactivity under the solar flux. The proposed project helps the investigator in his effort to continue to bring in several students from underrepresented groups each summer for a full-time research internship in the lab. The investigator also interfaces with several industrial partners to provide the undergraduate researchers with industrial laboratory experience.In this project, funded by the Chemical Catalysis Program, Dr. Mikhail Zamkov of Bowling Green State University focuses on the synergy of novel synthetic strategies and ultrafast spectroscopy techniques to explore a new class of photocatalytic materials utilizing composite colloidal nanostructures. The proposed nanomaterials combine several inorganic domains in a single nano-reactor designed to efficiently convert the solar radiation into a catalytically active state. The key innovation of the nanomaterial architecture lies in the plasmon-assisted light-harvesting scheme, which takes advantage of the strong electro-magnetic field that exists in metal nanoparticles to boost the production of excitons in the surrounding semiconductor shell. The excitation energy of the shell is then relayed to suitable oxidation/reduction catalysts on the surface. To ensure that different constituents of the composite nano-object work seamlessly, inter-domain interfaces are grown using molecular epitaxy. Such stoichiometric bonds, either covalent or ionic, reduce the density of defect states that dissipate the excitation energy enabling a high throughput of the absorbed radiation. The catalytic performance of the investigator's colloidal nanostructures are tested using common redox reactions in aqueous media, while the energy transfer processes are investigated using ultrafast spectroscopy techniques. As an active member of Building Ohio's Sustainable Energy Future and Science, Engineering & Technology Gateway Ohio programs, Professor Zamkov involves small teams of undergraduate students in this research project, introducing them to general concepts in ultrafast spectroscopy, material science, and chemical synthesis. Special efforts are made to involve minority students and students from underrepresented groups. Professor Zamkov also interfaces with several industrial partners to provide the undergraduate researchers with industrial laboratory experience.