INSPIRE Track 1: Microbial Sulfur Metabolism and its Potential for Transforming the Growth of Epitaxial Solar Cell Absorbers

INSPIRE 轨道 1：微生物硫代谢及其改变外延太阳能电池吸收体生长的潜力

• 批准号: 1344241
• 负责人: Peter Girguis
• 金额: $ 79.61万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1344241&HistoricalAwards=false
• 关键词: INSPIRE; Track; Microbial; Sulfur; Metabolism

AbstractThis INSPIRE award is partially funded by Biological Oceanography Program in Division of Ocean Sciences, in the Directorate of Geosciences; the Electronic and Photonic Materials Program in the Division of Materials Research, Directorate of Mathematical and Physical Sciences.A simple idea motivates this project: By characterizing the mechanisms underlying pyrite film deposition by subsurface microbes living at hydrothermal vents, can approaches be developed to controllably grow high-purity pyrite films that could be used to produce low-cost photovoltaic solar cells? Recent in situ studies at hydrothermal vents have found "subsurface" microbes associated with the deposition of large crystalline metal sulfides (up to 1.1 millimeters), including iron pyrite. In laboratory incubations, vent microbes specifically deposited pyrite (FeS2), devoid of Zn, Cu and other metals that were abundant in the liquid media. Abiotic incubations did not exhibit this specificity. The investigators hypothesize that, in situ, microbes deposit pyrite via a number of potential processes, including a physiological process called extracellular electron transfer (EET), wherein microbes shuttle electrons to/from minerals. In situ, EET-enabled microbes may use conductive minerals to electrically access oxidants, and deposit pyrite on these surfaces. Vents are thus natural bioelectrochemical cells, which grow metal sulfides via microbial and abiotic electrochemical processes, though the details and mechanisms remain to be determined. This project is aimed at elucidating the mechanisms underlying microbial FeS2 pyrite bio-deposition, and assessing how microbes might be used to deposit epitaxial films for solar cells absorbers. FeS2 pyrite has been identified as prospective low cost solar absorbers because of their abundance, suitable band-gap (~0.95 eV) and high optical absorbance. Microbial pyrite film deposition at lower temperatures (100 C) might offer a radically new, low cost approach to creating large area PV solar cells. Nothing is currently known about the mechanisms underlying microbial pyrite growth, though the large crystal sizes suggest epitaxial deposition is favored over re-nucleation implying that, once nucleated, epitaxial growth can occur. A series of experiments using natural vent microbial communities and isolates will be conducted to determine: A) environmental factors that influence bio-deposition; B) potential molecular mechanisms; C) the microstructural and electrical properties of these films; and D) whether bio-deposition by single species or consortia yields films of highest purity, size and homogeneity.Intellectual Merit: The project is both highly-integrated and transformative. It is relevant to our understanding of microbial sulfur cycling, as little is known about how microbes mediate crystalline pyrite formation and the degree to which this influences sulfur isotope geochemistry. Molecular studies will be used to interrogate relevant microbial metabolic processes and constrain the possible mechanisms of pyrite film growth, which is critical to advancing our ability to grow FeS2 films for device applications. Understanding the effects of substrate crystallography and electrical conductivity on the growth morphology will further inform our knowledge of microbial pyrite deposition. Notably, this research differ from existing biomimetic approaches. The studies are not focused on crystal growth via tethered peptides or synthetic extracellular matrices. Rather, they aim to advance our understanding of natural biodeposition, use the insights gained to grow pyrite materials and devices.Broader Impacts: Apart from the exciting and possibly transformative impact on creating alternative photovoltaic solar cells, this activity offers an unusual opportunity to perform research across current intellectual boundaries of microbial sciences and electronic / engineering materials. Graduate students will be thoroughly engaged in both these areas, with extensive mentoring from the PIs and the postdoc. Via numerous Harvard and NSF programs, the investigators will engage undergraduates in the research. Moreover, Professors Girguis and Clarke will use this project to teach a new course to freshman, focused on understanding and communicating interdisciplinary science. In this course, and in collaboration with the Harvard Museum of Natural History, students would design a public exhibit on how microbes make minerals and electricity, which would be evaluated by the museum staff and the some of the ~200,000 annual visitors on its efficacy, thus enabling the Harvard students to learn firsthand about communicating science, and informing the public about the relationships between science and engineering.

摘要这一Inspire奖部分由地球科学局的海洋科学部生物海洋学计划部分资助；材料研究部中的电子和光子材料计划，数学和物理科学局。一个简单的想法激发了该项目：通过表征生活在水热通风孔的地下微生物中的黄铁矿膜沉积机制，可以开发出可用于可控制的高硫酸含量的高硫酸含量的高硫酸含量的高铁膜，以生产低速度溶液溶液，以产生低效细胞溶液？最近在水热通风孔进行的原位研究发现，与大型晶体金属硫化物（包括1.1毫米）的沉积相关的“地下”微生物，包括铁矿铁矿。在实验室孵化中，排气微生物特异性沉积黄铁矿（FES2），该硫酸盐，没有Zn，Cu和其他液体培养基中丰富的金属。非生物孵育没有表现出这种特异性。研究人员假设，在原位，微生物通过许多潜在过程将黄铁矿沉积，包括一个称为细胞外电子转移（EET）的生理过程，其中微生物将电子穿梭于矿物质/从矿物质。原位，支持EET的微生物可以使用导电矿物来电气获取氧化剂，并将黄铁矿沉积在这些表面上。因此，通风孔是天然的生物化化学细胞，它们通过微生物和非生物电化学过程生长金属硫化物，尽管细节和机制仍有待确定。该项目旨在阐明微生物FES2黄铁矿生物沉积的基础机制，并评估如何使用微生物为太阳能电池吸收剂沉积外延膜。 FES2黄铁矿由于其丰度，合适的带隙（〜0.95 eV）和高光吸光度而被确定为前瞻性低成本吸收剂。较低温度（100 C）处的微生物黄铁矿膜沉积可能会提供一种新的，低成本的方法来创建大面积的PV太阳能电池。尽管大晶体尺寸表明外延沉积比重新核酸盐相比，目前对微生物黄铁矿生长的机制目前尚无任何了解，这表明一旦成核，可能会发生外延生长。 将进行一系列使用天然排气微生物群落和分离株的实验，以确定：a）影响生物沉积的环境因素； b）潜在的分子机制； c）这些膜的微结构和电性能； d）单个物种或财团的生物沉积是否产生最高纯度，大小和同质性的薄膜。智能优点：该项目既高度融合又具有变革性。这与我们对微生物硫循环的理解有关，因为微生物如何介导晶体黄铁矿的形成以及影响硫同位素地球化学的程度知之甚少。 分子研究将用于询问相关的微生物代谢过程，并限制黄铁矿膜生长的可能机制，这对于促进我们在设备应用中生长FES2膜的能力至关重要。了解底物晶体学和电导率对生长形态的影响将进一步了解我们对微生物黄铁矿沉积的了解。 值得注意的是，这项研究与现有的仿生方法不同。这些研究并非通过束缚肽或合成细胞外基质来关注晶体生长。相反，他们旨在提高我们对自然生物充足的理解，利用获得的洞察力来种植黄铁矿材料和设备。Boader的影响：除了对创建替代光伏太阳能电池产生令人兴奋的和可能的变革性影响外，此活动还提供了一个与众不同的机会，可以在当前的微型科学和电子 /电子 /电子 /电子 /电子 /机器人材料的智力边界进行研究。研究生将彻底参与这两个领域，并在PI和博士后进行广泛的指导。通过众多哈佛和NSF计划，调查人员将在研究中吸引本科生。此外，Girguis和Clarke教授将使用该项目向新生讲授新课程，专注于理解和交流跨学科科学。在本课程中，以及与哈佛大学自然历史博物馆合作，学生将设计一个公开展览，内容涉及微生物如何制造矿产和电力，博物馆工作人员以及约200,000万名年度访客中的一些访客就其功效进行了评估，从而使哈佛大学的学生能够学习有关传播科学的Firsthand，并了解公众有关科学的关系，并了解科学和发动机之间的关系。