CAREER: Tuning Photoredox Properties of Carbazolic Porous Organic Frameworks for Visible-Light-Mediated Catalysis

在材料研究部固体与材料化学项目的支持下，研究小组提出开发一类新的有机多孔材料。咔唑多孔有机骨架（Cz-POFs）。Cz-POFs的扩展π共轭、三维聚咔唑网络以及可定制的电子和光学性质的独特组合使其在太阳能收集、转换和利用中具有重要的潜在应用。这些基础研究工作与一系列教育活动相结合，包括材料研究中的研究生和本科生的培训和指导，创建可访问的，适应性强的和廉价的多孔材料模型套件，以支持多种推广活动，并向不同年龄和知识水平的观众传达对材料化学的基本理解，以及在内布拉斯加大学林肯分校建立化学大使计划，以提高公众对材料化学在日常生活中的作用的认识和赞赏。技术摘要拟议的研究解决了建立Cz-POFs作为新一代太阳能光活性材料的关键知识差距，能量收集、转换和利用。研究小组已经证明，与线性对应物相比，原型Cz-POFs具有大的表面积，增强的介孔性和高稳定性，沿着强的还原能力和可回收性，使它们非常适合于许多光电应用。本研究的具体目标是开发合成方法（1）通过理论指导的化学修饰进一步提高Cz-POFs的氧化能力，（2）通过调节分子内D-A相互作用开发具有增强的光氧化还原性能的给体-受体Cz-POFs，以及（3）增强Cz-POFs的光氧化还原催化活性。这项研究提供了一个更好的理解的合成因素，控制电子和光学性能，光诱导能量和电子转移，和光氧化还原催化活性与Cz-POFs和其他π共轭聚合物网络一般。这项研究还有助于使用POFs从二氧化碳中光化学生产清洁有机燃料以及太阳能水分解。此外，建立了一个综合性的在线数据库多孔有机框架资源，促进了多孔材料的跨学科研究。

Non-technical AbstractWith support from the Solid State and Materials Chemistry program in the Division of Materials Research, the research team proposes to develop a new class of organic porous material?carbazolic porous organic frameworks (Cz-POFs). The unique combination of extended pi-conjugation, three-dimensional polycarbazole networks, and tailorable electronic and optical properties of Cz-POFs enables their significant potential applications in solar energy harvesting, conversion, and utilization. These basic research efforts are integrated with a series of educational activities including the training and mentoring of graduate and undergraduate students in materials research, the creation of accessible, adaptable, and inexpensive model kits of porous materials to support multiple outreach activities and to convey a basic understanding of materials chemistry to audiences of different ages and knowledge levels, and the establishment of a Chemistry Ambassador program at the University of Nebraska-Lincoln to improve awareness of and public appreciation for the role of materials chemistry in everyday lives.Technical AbstractThe proposed research addresses critical knowledge gaps for establishing Cz-POFs as a new generation of photoactive materials for solar-energy harvesting, conversion, and utilization. The research team have demonstrated that, compared to their linear counterparts, prototypic Cz-POFs exhibit large surface area, enhanced mesoporosity, and high stability, which, along with strong reductive ability and recyclability, make them well suited for many optoelectronic applications. The specific aims of this research are centered on developing synthetic approaches (1) to further increase the oxidative ability of Cz-POFs through theory-guided chemical modification, (2) to develop donor-acceptor Cz-POFs with enhanced photoredox properties by adjusting intramolecular D-A interactions, and (3) to enhance photoredox catalytic activities of Cz-POFs. This research provides a better understanding of synthetic factors that control the electronic and optical properties, photoinduced energy and electron transfer, and photoredox catalytic activities associated with Cz-POFs and other pi-conjugated polymer networks in general. This research also contributes to the use of POFs for photochemical production of clean organic fuels from carbon dioxide as well as solar water splitting. Further, the building of a comprehensive online database Porous Organic Framework Resource facilitates interdisciplinary research on porous materials.