Photochemistry in nanotechnology and catalysis

纳米技术和催化中的光化学

• 批准号: RGPIN-2018-05594
• 负责人: Scaiano, Juan
• 金额: $ 6.85万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=664406
• 关键词: Photochemistry; nanotechnology; catalysis

The paradigms of photochemistry and physical organic chemistry guide our strategies for the synthesis, modification and utilization of nanostructured materials incorporating semiconductor, plasmonic and acid-base structures for catalysis and health applications. New materials are designed for specific applications in catalysis, water splitting/treatment and health. The synthesis of complex nanostructures, especially using photochemistry, combine semiconductors such as TiO2 and Nb2O5 with metals or their oxides (Au, Ag, Cu, Pt, Pd, Ru, Co, Ni, & Co). These new materials enable all aspects of our work and provide an excellent basis for HQP training.***Catalysis plays a major role in our research, including redox, C-H activation and C-C coupling reactions. Our success in photoredox catalysis reactions replacing expensive transition metal catalysts with inexpensive dyes and semiconductors led us to develop versatile catalysts such as Pd-on-TiO2 where heat or different excitation wavelengths control the reaction outcome, while Cu-on-TiO2 that can drive click chemistry on demand under visible light. Different metals and their combinations open new opportunities to address organic chemistry challenges. ***We look intimately at chemical transformations, avoiding the ‘black-box' approach to catalysis. Among these, from the molecule to the mole takes advantage of knowledge acquired using single molecule spectroscopy (SMS) and laser flash photolysis (LFP) to inspire bench scale improvements. We plan to examine organic reactions that can benefit from these approaches. We can manufacture and evaluate new catalyst performance, and use SMS and imaging methodologies to inspire bench scale advances.***An area of interest is water splitting/decontamination that have been frequently treated as orthogonal fields, using sunlight to either produce H2 or decontaminate water, yet, they are intimately related. Research on water splitting has utilized solar light, semiconductor catalysis and frequently “sacrificial electron donors”, molecules that facilitate H2 evolution at the expense of the degradation of valuable chemicals. In a novel approach, we propose that water contaminants can act as sacrificial donors, enhancing H2 production while simultaneously decontaminating water (chemically & bacteriologically). Initial tests show that waters from local rivers produce more H2 than pure water, as minor contaminants act as sacrificial donors. In the development of photocatalysts, we view water splitting and purification as two facets of the same problem. We propose H2 production and water decontamination as coupled processes.***In health and cosmetics our studies focus on antibacterial properties of nanomaterials and the effect of organic shells on cosmetic materials, such as lignin-coated TiO2, a major sunscreen ingredient with a reputation for adverse health effects that lignin can prevent.

光化学和物理有机化学的范例指导了我们的策略，以合成、修饰和利用纳米结构材料，将半导体、等离子体和酸碱结构用于催化和健康应用。新材料是为催化、水分解/处理和健康领域的特定应用而设计的。复杂纳米结构的合成，特别是利用光化学，将半导体如TiO2和Nb2O5与金属或它们的氧化物（Au, Ag, Cu, Pt, Pd, Ru, Co, Ni, & Co）结合起来。这些新材料有助于我们工作的各个方面，并为HQP培训提供了良好的基础。***催化在我们的研究中起主要作用，包括氧化还原、C-H活化和C-C偶联反应。我们在光氧化还原催化反应中取得的成功用廉价的染料和半导体取代了昂贵的过渡金属催化剂，这使我们开发了多功能催化剂，如Pd-on-TiO2，其中热量或不同的激发波长控制反应结果，而Cu-on-TiO2可以在可见光下按需驱动点击化学。不同的金属及其组合为解决有机化学挑战提供了新的机会。***我们密切关注化学转化，避免使用“黑箱”方法进行催化。其中，从分子到摩尔利用利用单分子光谱学（SMS）和激光闪光光解（LFP）获得的知识来激发实验规模的改进。我们计划研究可以从这些方法中受益的有机反应。我们可以制造和评估新的催化剂性能，并使用SMS和成像方法来激发实验规模的进步。***感兴趣的领域是水分解/去污，这通常被视为正交领域，利用阳光产生H2或去污水，然而，它们是密切相关的。水分解的研究利用了太阳能、半导体催化和经常出现的“牺牲电子供体”，即以牺牲有价值化学物质的降解为代价促进H2进化的分子。在一种新的方法中，我们提出水污染物可以作为牺牲供体，在提高H2产量的同时净化水（化学和细菌）。最初的测试表明，来自当地河流的水比纯净水产生更多的氢气，因为轻微的污染物充当了牺牲的供体。在光催化剂的发展中，我们认为水的分解和净化是同一个问题的两个方面。我们提出氢气生产和水净化作为耦合过程。***在健康和化妆品方面，我们的研究重点是纳米材料的抗菌性能和有机外壳对化妆品材料的影响，例如木质素涂层的TiO2，一种主要的防晒成分，木质素可以预防对健康的不良影响。