Role of nanominerals on photochemical derived atmospheric NH3 and N2O

大量证据表明，全球氮循环并不平衡。农业的集约化和化石燃料燃烧排放量的增加是造成这种不平衡的主要原因，因为这两种人为活动在上个世纪使活性氮的排放量增加了三倍。此外，这些有害的环境污染物是形成某些气溶胶的原因，对自然生态系统和人类健康都有负面影响。工程解决这一不平衡的主要挑战在于量化和识别大气和土壤圈中的所有全球氮通量。这就需要对自然和人为源和汇进行高分辨率的测量。这项研究旨在量化由于土壤纳米矿物和阳光之间的纳米级相互作用而产生的天然氮基大气排放率。目前，对人为排放源的测绘一般比对自然或半自然排放源的测绘更为准确。因此，进一步努力确定哪些纳米现象有助于土壤中氮的形成和排放，对于促进我们对全球氮循环的理解至关重要。这项工作还将支持本科教育，作为通过格鲁吉亚科技的食品能源水倡议，这是通过服务，学习，维持计划启用顶点项目的基础。这个顶点项目将吸引包括工程和社会科学在内的一系列学科的本科毕业生。此外，这项工作旨在通过与亚特兰大广泛的倡议科学-艺术-奇迹合作，吸引非科学界的参与。通过这个项目，研究人员将与艺术家合作，将关键的科学发现转化为艺术作品，并在亚特兰大科学节上展出。该项目的主要研究目标是了解土壤和沙子中的光催化地球丰富的纳米矿物如何促进活性氮的排放。具体来说，PI将研究矿物，土壤和大气特性在增加纳米矿物对氨和一氧化二氮生产的活性方面所起的作用。通过光（电）催化测试，探讨常见纳米矿物的纳米级结构与性能的关系，以辨别矿物尺寸和表面纳米结构对催化活性的影响。深入的第一性原理计算和大气测试也将阐明哪些纳米级化学机制和物理现象促进阳光驱动的活性氮产生和土壤和沙子的排放。这一基本认识将深入了解陆地纳米矿物在介导自然氮循环中的作用，为陆地和大气环境中更准确的营养通量模型提供基础。该项目将寻求对土壤和农业在大气污染方面的作用建立一种整体观点。将通过外联和教育工作加强这项工作的影响。研究结果将通过一个可公开访问的网站和YouTube视频来突出显示，这些视频展示了关键的研究结果，并提出了可以用家用物品进行的简单实验。该奖项反映了NSF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。

Significant evidence suggests that the global nitrogen cycle is not balanced. The intensification of agriculture and rising emissions from the burning of fossil fuels are largely responsible for this imbalance, as both of these anthropogenic activities have enhanced reactive nitrogen emissions by a factor of three over the last century. Furthermore, these harmful environmental pollutants are responsible for the formation of certain aerosols, which have negative implications for both natural ecosystems and human health. A chief challenge in engineering solutions to this imbalance lies in quantifying and identifying all global nitrogen fluxes in the atmosphere and pedosphere. This requires high-resolution measurements of both natural and anthropogenic sources and sinks. This research will aim to quantify the rate of natural nitrogen-based atmospheric emissions that arise due to nanoscale interactions between soil nanominerals and sunlight. Currently, anthropogenic sources are generally more accurately mapped than emissions from natural or semi-natural sources. Therefore, further efforts to identify which nanoscale phenomena aid the formation and nitrogen-based emission in soils is important to advance our understanding of the global nitrogen cycle. The work will also support undergraduate education, serving as the basis of a capstone project through Georgia Tech's Food-Energy-Water initiatives, which is enabled through the Serve-Learn-Sustain program. This capstone project will engage undergraduate seniors from a range of academic disciplines including engineering and social sciences. In addition, this work seeks to engage the non-scientific community through a collaboration with the Atlanta wide initiative Science-Art-Wonder. Through this program, researchers will collaborate with artist to transform key scientific findings into art pieces that will be displayed at the Atlanta science festival. The main research objective of this project is to understand how photocatalytic earth-abundant nanominerals in soils and sands contribute to reactive nitrogen emissions. Specifically, the PI will investigate the role mineral, soil and atmospheric properties play in increasing the activity of nanominerals for ammonia and nitrous oxide production. The nanoscale structure-property relationships of common nanominerals will be probed through photo(electro)catalytic testing to discern the impact mineral size and surface nanostructure have on catalytic activity. In depth first-principles calculations and atmospheric testing will also elucidate which nanoscale chemical mechanisms and physical phenomena promote sunlight driven reactive nitrogen production and emission from soils and sands. This fundamental understanding will provide insight into the role terrestrial nanominerals play in mediating the natural nitrogen cycle, providing a foundation for more accurate models of nutrient fluxes in terrestrial and atmospheric settings. The project will seek to establish a holistic view of the role soils and agriculture play on atmospheric pollution. The impact of the work will be enhanced by outreach and educational efforts. The findings will be highlighted through a publicly accessible website and YouTube videos that demonstrate key findings and suggest simple experiments that can be performed with household items.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.