Photoelectrochemically Driven Water-Oxidation Catalysis by Perylene Diimide Plus Cobalt-Oxide Based Photoanodes: Fundamental Studies En Route to Second-Generation Systems

化学部的化学催化计划支持理查德·G·芬克教授的项目。芬克教授是科罗拉多州立大学化学系的教员。他的研究重点是开发廉价、高效、富含稀土元素的材料，这些材料可以收集太阳能，然后利用这些能量将水氧化成其氧气和氢气成分。然后，氢气可用作可再生能源。该项目涉及使用廉价、坚固的二苯二亚胺染料(例如，在红色到黑色的汽车涂料中使用)来捕捉太阳能，以及使用地球上丰富的氧化钴作为水氧化催化剂。该项目集无机、有机、材料化学和化学催化于一体，是培养能够进行能源相关研究的下一代基础广泛的科学家的理想选择。对少数族裔服务机构的大学生的接触是该项目不可或缺的一部分。路易斯堡学院是一家西班牙裔服务机构，北科罗拉多大学是一所以本科生为主的大学，15%的拉美裔学生和34%的第一代学生。从更深的技术层面来看，作为研究三个具体目标的一部分，三个主要问题被解决：第一，精心挑选的七种二茂铁类染料中，哪一种可以产生最好的光电电解池？为什么？重要的是，对于有机染料膜与无机氧化钴水氧化催化剂的偶联，所使用的二苯二亚胺染料中存在的膦酸官能团是关键的吗？其次，如果采用染料敏化的光电电解池结构，在这种结构中，可以将一种二苯二亚胺染料单分子层吸附到以钛、锡和钨为基础的半导体金属氧化物的高表面积烧结纳米颗粒薄膜上，那么光电电池的性能是否会得到极大的改善？或者，另一种假设是否证明了增强的空穴/电子复合在染料敏化光电电池结构中占主导地位？如果是，原因何在？第三，有机光收集器是否具有足够的抗氧化稳定性，值得在未来的水氧化催化和其他此类光阳极中占据重要地位？与其他材料相比，有机染料具有成本低、合成灵活、性能易于调节等显著优点。这些光电池中活跃的失活途径是什么，因此，基于这种有机捕光材料的光阳极寿命更长的最佳策略是什么？教育外展包括芬克教授受邀访问的多所院校的本科生和一年级研究生的讲座，主题是“通过恰当的科学方法进行批判性阅读和分析技能”。

The Chemical Catalysis Program of the Chemistry Division supports the project by Professor Richard G. Finke. Professor Finke is a faculty member in the Department of Chemistry at Colorado State University. His research is focused on developing cheap, efficient, earth-element-abundant and hence low cost materials that can collect solar energy, and then use that energy to oxidize water into its oxygen and hydrogen components. The hydrogen then serves as a renewable energy source. The project involves the use of cheap, robust perylene diimide dyes (used, for example, in red to black car paints) to capture the solar energy, plus earth-abundant cobalt oxide as the water-oxidation catalyst. The project is at the interface of inorganic, organic, and materials chemistries plus chemical catalysis, making it ideal for training the next generation of broad-based scientists able to perform energy-related research. Outreach involving college students at the minority serving institutions of Fort Lewis College, a Hispanic Serving institution, and the University of Northern Colorado, a primarily undergraduate university with 15% Hispanic and 34% first-generation students, is an integral part of the project.Looking deeper technically, three main questions are addressed as part of the three specific aims of the research: First, which of seven perylene-type dyes, carefully selected for further investigation, yields the best photoelectrolysis cell and why? Importantly, are phosphonate functional groups present in the perylene diimide dye employed crucial for coupling the organic dye film to the inorganic cobalt oxide water-oxidation catalyst? Second, is the photoelectrolysis cell performance greatly improved if one employs a dye-sensitized photoelectrolysis cell architecture in which a perylene diimide dye monolayer can be adsorbed onto a high-surface-area sintered nanoparticle film of semiconducting metal oxides based on titanium, tin, and tungsten? Or, does the alternative hypothesis prove true that enhanced hole/electron recombination dominates in the dye-sensitized photoelectrolysis cell architecture? If so, why? Third, do organic light-harvesters possess sufficient stability against oxidation to merit an important position in future water-oxidation catalysis and other such photoanodes? Organic dyes have notable advantages over other materials including low cost, synthetic flexibility and easily tunable properties. What are the deactivation pathways active in these photocells and, thus, best strategies for longer photoanode lifetimes based on such organic light-harvesting materials? The education outreach includes lectures that Professor Finke gives to undergraduates and first-year graduate students, at multiple institutions he has been invited to visit, addressing the crucial topic of "Critical Reading and Analysis Skills via a Proper Scientific Method."