Understanding Photo-conversion Processes in Biomimetic Photoelectrochemical Nanomaterials

PI：Choi提案编号： 1134376基于太阳光到电的光电化学转换的太阳能电池遭受相对窄的光吸收和电池退化，这降低了器件性能和寿命。 在自然界中，光合作用已经解决了许多这些问题。 光合作用是生物介导的光电化学过程，用于将阳光转化为电子。 自然光合作用已经完善了强大的分子机制，这些分子机制使用发色团阵列来增强光激发能量收集，这些发色团通过自我再生来抵消光损伤的影响。目前光电化学电池的局限性可以更好地理解和潜在的改进，模仿自然光合作用与人工光系统。 本研究的总体目标是开发通用的设计规则，以构建具有改善的整体光转换效率和使用寿命的人工光系统。本研究旨在通过生物分子纳米纤维技术，利用合成生色团纳米材料模拟天然光合作用的光吸收/转换和自我再生过程。 具体而言，光色素和量子线将通过可编程DNA分子识别技术可逆地组装，形成能够全色吸收和系统修复的光电化学纳米结构。 例如，在单壁碳纳米管上选择性卟啉发色团的基于DNA的组装可以与G-四链体相互作用，以促进纳米级的电荷转移。 通过这种方法，将开发各种能够模仿天然光系统的结构和功能的合成光转换纳米结构，并且将使用能量和电荷传输过程的超快泵浦-探测测量来研究它们的光吸收和转换过程。 这些数据将被分析，以阐明光转换过程的热力学和动力学，并生成用于构建人工光合单元的设计规则。 更广泛的影响拟议的活动将把研究工作与旨在提高公众对人工光合作用的认识的教育和外展活动结合起来。 具体而言，将为普渡大学主办的“介绍女孩工程日”和“发现日”开发高中生实践模块，研究成果也将在nanoHUB（NSF资助的普渡纳米技术网站）上展示。 女性和代表性不足的本科生将通过普渡大学的女性工程和少数民族工程项目被招募参与研究。

PI: ChoiProposal Number: 1134376Solar cells based on photoelectrochemical conversion of sunlight to electricity suffer from relatively narrow light absorption and cell degradation, which reduces device performance and lifetime. In nature, photosynthesis has solved many of these problems. Photosynthesis is a biologically-mediated photoelectrochemical process for conversion of sunlight into electrons. Natural photosynthesis has perfected robust molecular machineries that enhance photo-excitation energy collection using an array of chromophores that counteract the effect of photo-damage via self-regeneration. The current limitations of photoelectrochemical cells can be better understood and potentially improved by mimicking natural photosynthesis with artificial photosystems. The overall goal of this research is to develop general design rules to build artificial photosystems with improved overall photo-conversion efficiency and service lifetime.This research seeks to mimic the photo-absorption/conversion and self-regeneration processes of natural photosynthesis with synthetic chromophore nanomaterials through biomolecular nanofabrication techniques. Specifically, photo-pigments and quantum wires will be reversibly assembled via programmable DNA molecular recognition techniques, forming photoelectrochemical nanostructures capable of panchromatic absorption and system repair. For example, DNA-based assembly of selective porphyrin chromophores on single-walled carbon nanotubes can interact with G-quadruplexes to facilitate charge transfer at the nanoscale. By this approach, a variety of synthetic photo-conversion nanostructures capable of mimicking the structure and function of natural photosystems will be developed, and their photo absorption and conversion processes will be studied using ultrafast pump-probe measurement of the energy and charge transport processes. This data will be analyzed to elucidate the thermodynamics and kinetics of photo-conversion processes, and generate design rules for constructing artificial photosynthetic units. Broader ImpactsThe proposed activities will couple the research efforts to educational and outreach activities designed to advance the public understanding of artificial photosynthesis. Specifically, hands-on modules for high-school students will be developed for Introduce a Girl to Engineering Day and Discovery Days hosted by Purdue University, and research outcomes will also be featured on nanoHUB, an NSF-funded, Purdue-based nanotechnology website. Female and underrepresented undergraduate students will be recruited for participation in the research through the Women in Engineering and Minority Engineering Programs at Purdue University.