Collaborative Research: Understanding the Synergistic Effect of Graphene Plasmonics and Nanoscale Spatial Confinement on Solar-Driven Water Phase Change

海水淡化和废水处理依赖于大量能源的消耗。对于分布式水处理系统，成本可能比集中式工厂高出十倍。利用太阳能等可再生能源完全或部分替代水处理所需能源的能力可能会对全球能源和水供应的可持续性产生重大影响。高效的太阳能热能转换蒸汽产生技术是一项重要的绿色技术，可以减少海水淡化和废水处理的能源需求。然而，低蒸汽蒸发速率仍然是许多实际应用的挑战。石墨烯等离子体，指的是石墨烯薄片受光激发时的集体电子振荡，被认为有助于提高石墨烯纳米金属结构的太阳能到热转换效率。在本研究项目中，计算机模拟和实验将结合起来，了解石墨烯等离子体和空间限制对水的热力学性质和太阳能驱动的水蒸发速率的协同效应。从这项研究中获得的知识将有助于开发用于太阳能热蒸发应用的新型石墨烯等离子体材料。该项目还将包括重要的教育活动，如面向当地K-12学生和教师的拓展项目，以及带有开放式设计项目的本科生研究项目。本研究项目的目标是了解由于沿独特纳米金属边缘的极端光限制而引起的等离子体共振诱导的局部电场是如何排列或不排列在多孔结构中垂直独立的石墨烯薄片之间的水分子偶极子的。该研究项目集成了完整的电磁波计算、分子模拟和实验验证。一些具体目标包括了解石墨烯等离子体引起的纳米承压水热力学性质变化对蒸汽蒸发速率影响的基本机制。将使用电磁波计算和分子模拟相结合的方法对该系统进行建模。此外，研究人员将通过独特合成的多孔石墨烯纳米金属结构中由异常近红外等离子体介导的太阳能驱动的水相变实验来验证建模结果。该项目有望揭示石墨烯等离子体共振介导水相变的新机制，这可能有助于改进太阳能热能转换技术。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Water desalination and wastewater treatment rely on the consumption of significant amounts of energy. For distributed water treatment systems, the cost can be ten times higher than that of the centralized plants. The ability to use renewable energy such as solar energy to replace completely, or in part, the energy needed for water treatment may lead to substantial impacts on the sustainability of the global energy and water supply. Efficient solar-thermal energy conversion for vapor generation is an important green technology that could reduce the energy demands of water desalination and wastewater treatment. However, the low vapor evaporation rate remains a challenge for many practical applications. Graphene plasmonics, which refers to the collective electron oscillation in graphene flakes when excited by light, is believed to contribute to the enhanced solar-to-thermal conversion efficiency of graphene nanopetal structures. In this research project, computer modeling and experiments will be combined to understand the synergistic effects of graphene plasmonics and spatial confinement on thermodynamic properties of water and the solar-driven water evaporation rate. The knowledge gained from this study will assist in developing new graphene plasmonic materials for solar thermal evaporation applications. The project will also include significant educational activities, such as outreach programs for local K-12 students and teachers and undergraduate research programs with open-ended design projects.The goal of this research project is to understand how the plasmon resonance-induced local electric field due to extreme light confinement along the unique nanopetal edges either aligns or dis-aligns water molecular dipoles confined between the vertically freestanding graphene flakes in a porous structure. The research project integrates full electromagnetic wave calculations, molecular simulations, and experimental validation. Some of the specific objectives include understanding the fundamental mechanisms governing the influence of graphene plasmonics-induced thermodynamic property change of nano-confined water on vapor evaporation rate. A combination of electromagnetic wave calculations and molecular simulations will be used to model this system. Additionally, the researchers will validate the modeling results through experiments on solar-driven water phase change mediated by anomalous near-infrared plasmons in uniquely synthesized porous graphene nanopetal structures. This project is expected to reveal new mechanisms of graphene plasmon resonance-mediated water phase transition, which may contribute to improving solar-thermal energy conversion technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.