Photolytic Nanoconjugate Fuel Generators

该项目的重点是设计一种光电化学装置，该装置有可能扩大到“光解农场”的规模，能够以商业规模生产从光催化分解水中获得的氢。产生的氢（H2）可以直接用于发电（即太阳能燃料）或作为生产可持续液体燃料或化学品的原料。该项目当前的重点将是了解工作机制和优化基于金属纳米粒子装饰的半导体纳米线的所谓纳米共轭器件的效率。该项目将与一个商业伙伴合作，对学生进行培训和早期制造可行性的调查，并将为K-12学生提供纳米粒子和显微镜方面的几项推广活动。这项研究是建立在电子、静电和等离子体机制的结合可以通过利用纳米共轭器件结构和适当的材料来实现的假设之上的。研究人员实验室的初步结果已经证明，在445 nm辐射下，使用溶胶-凝胶制备的氧化钒纳米线涂覆纳米金，H2与O2的比例为2.0，光氢效率为5.6%。纳米线-纳米颗粒装置的独特结构使效应和机制的新组合能够潜在地提高光解效率。需要研究的机制有：1)由于超低纳米粒子电容导致的电子能级自对准，2)表面电荷使能级与氧化还原水平对齐，以及3)化学界面阻尼直接等离子体驱动的还原。这些使能机制的阐明可能会影响其他新型光催化剂的开发工作，并允许更多的光催化材料和结构能够光解。该项目将利用和研究V2O5-H2O作为光阳极，它本质上是一种鲜为人知的半导体。选择要研究的系统时考虑到了扩大规模，因为光解纳米缀合物可以以水悬浮液的形式以低成本制造，随后可以填充在透明的外壳面板中，并扩大到燃料农场。为此，该项目将与马里兰州InnoVital Systems公司合作，开发学生实习机会。在InnoVital工程师的指导下，工科本科生将参与设计纳米器件悬架的玻璃/塑料外壳，该外壳将作为光解面板的先进原型。外展活动将集中于与俄克拉何马州WONDERtorium合作开展的为期一天的夏令营，在那里，孩子们将使用项目组开发的工具包制作纳米颗粒，并使用光学和电子显微镜检查纳米颗粒。此外，该项目将通过俄克拉何马州路易斯·斯托克斯少数民族参与学者联盟项目（OK-LSAMP），让代表性不足的学生参与研究。

The project is focused on designing a photoelectrochemical device that can potentially be scaled up to the size of 'photolysis farms' capable of the commercial-scale production of hydrogen obtained from the photocatalytic splitting of water. The produced hydrogen (H2) could be used directly for energy generation (i.e. solar fuel) or as a feedstock for the generation of sustainable liquid fuels or chemicals. The immediate focus of the project would be on both understanding the working mechanism and optimizing the efficiency of so-called nanoconjugate devices based on semiconductor nanowires decorated with metal nanoparticles. The project will involve collaboration with a commercial partner for student training and investigation of early stage manufacturing feasibility, and will also incorporate several outreach activities on nanoparticles and microscopy for K-12 students.The research is built on the hypothesis that a combination of electronic, electrostatic, and plasmonic mechanisms can be achieved by utilizing the nanoconjugate device structure with appropriate materials. Preliminary results from the investigator's laboratory have already demonstrated 5.6% light-to-hydrogen efficiency with a H2 to O2 ratio of 2.0 under 445 nm radiation using sol-gel prepared vanadium oxyhydrate nanowires coated with nanogold. The unique architecture of the nanowire-nanoparticle device enables a novel combination of effects and mechanisms that can potentially increase photolytic efficiency. Mechanisms to be investigated are: 1) self-alignment of electron energy levels due to ultralow nanoparticle capacitance, 2) surface-charge-enabled alignment of energy levels with redox levels, and 3) direct plasmon-driven reduction by chemical interface damping. The elucidation of these enabling mechanisms should potentially impact other novel photocatalyst development efforts and allow for a larger set of photocatalytic materials and structures capable of photolysis. The project will utilize and investigate V2O5-H2O as the photoanode, which is essentially a little-known semiconductor. The system to be investigated has been chosen with scale-up in mind, as the photolytic nanoconjugates can be manufactured at low cost in the form of an aqueous suspension, which subsequently can be filled in transparent enclosure panels and scaled up to a fuel farm. To this end, the project will collaborate with InnoVital Systems, Inc. of Maryland to develop student internships. Under the direction of the InnoVital engineers, undergraduate engineering students will be engaged in designing a glass/plastic enclosure for the nanodevice suspension that will serve as an advanced prototype of the photolytic panel. Outreach activities will center on one-day summer camps carried out in collaboration with Oklahoma WONDERtorium, where the children will make nanoparticles with kits developed by the project team and examine their nanoparticles using optical and electron microscopy. Additionally, the project will engage underrepresented students in research through the Oklahoma Louis Stokes Alliance for Minority Participation Scholars Program (OK-LSAMP).