Surface science studies of the photo physics of copper oxides: toward sustainable CO2 recycling

利用太阳能将二氧化碳和水转化为有用的化学品和燃料，可以为可持续的碳循环提供一条途径，同时维持化学和运输工业的现有基础设施。有效利用太阳能来破坏稳定的二氧化碳键是这一过程的第一步，需要调整用于该反应的催化剂的光物理性质。在这个项目中，教授。俄亥俄州立大学的古普塔和阿斯塔吉里正在研究催化剂表面结构与太阳能转化为二氧化碳分子之间的关系。目标是了解促进这种能量转移和促进二氧化碳转化的因素。作为该项目的一部分，pi正在训练研究生结合实验和理论来解决重要的能源产生和转换问题。此外，pi正在吸引K-12和本科水平的学生，作为扩大学生参与STEM职业的努力的一部分。作为俄亥俄州立大学TEK8项目的一部分，研究生们正在开发模块，以吸引对STEM职业感兴趣的K-12学生。此外，作为俄亥俄州立大学暑期研究机会计划的一部分，未被充分代表的本科生正在被招募参加暑期研究。在美国国家科学基金会化学部化学催化项目的资助下，来自俄亥俄州立大学的Gupta博士和Asthagiri博士正在开发一个结合实验和理论的项目，旨在对Cu氧化物的局部表面结构和CO2分子的光激发之间的关系有一个基本的了解。Cu氧化物薄膜在超高真空（UHV）中以受控的方式生长，允许引入各种缺陷（例如空位，Cu氧化物薄膜化学计量的变化和掺杂）。扫描隧道显微镜（STM）与局部光照明提供直接图像的表面前后照明。密度泛函理论（DFT）计算有助于解释STM的图像和光谱，以联系局部Cu氧化物位点的电子状态与产生的CO2光化学之间的关系。此外，DFT还被用于探索Cu氧化物膜的改性，以增强CO2光活化；这些预测正在实验中进行测试，目的是建立用于CO2光还原的最佳氧化铜纳米结构的预测模型。作为该项目的一部分，pi积极参与研究生和本科生研究和开发模块中代表性不足的群体的招募，以通过俄亥俄州立大学的TEK8计划培养K-12学生对STEM职业的兴趣。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。

Solar conversion of CO2 and water to useful chemicals and fuels can provide a pathway to a sustainable carbon cycle, while maintaining existing infrastructure in the chemical and transport industries. Efficient use of solar energy to break the stable CO2 bonds is the first step in this process and requires tailoring the photophysical properties of the catalysts used for that reaction. In this project, Profs. Gupta and Asthagiri of Ohio State University are working to understand the relationship between catalyst surface structure and solar energy transfer into the CO2 molecule. The goal is to understand the factors that promote this energy transfer and promote CO2 conversion. As part of this project, the PIs are training graduate students to combine experiment and theory to tackle important energy generation and conversion problems. In addition, the PIs are engaging students from the K-12 and undergraduate level as part of an outreach effort to diversify student participation in STEM careers. Graduate students, as part of Ohio State's TEK8 program, are developing modules to engage K-12 students interest in STEM careers. In addition, underrepresented undergraduate students are being recruited for summer research as part of Ohio State's Summer Research Opportunities Program. With funding from the NSF Chemical Catalysis program of the Chemistry Division, Dr. Gupta and Asthagiri from The Ohio State University are developing a program that combines experiment and theory aimed to gain a fundamental understanding of the relationship between local surface structure of Cu oxides and the photoexcitation of CO2 molecules. Cu oxide thin films are grown in a controlled fashion in ultrahigh vacuum (UHV) that allows for the introduction of various defects (e.g. vacancies, variation in Cu oxide film stoichiometry, and dopants). Scanning tunneling microscopy (STM) with local photoillumination provide direct images of the surface before and after illumination. Density functional theory (DFT) calculations are assisting in interpreting both the images and spectroscopy from STM to link the relationship between the electronic states of the local Cu oxide site and the resulting CO2 photochemistry. In addition, DFT is being used to explore modifications to the Cu oxide films that enhance CO2 photoactivation; these predictions are being tested experimentally with the goal to establish a predictive model for optimal Cu oxide nanostructures for CO2 photoreduction. As part of this project, the PIs are actively engaged in the recruitment of underrepresented groups in graduate and undergraduate research and developing modules to foster the interest in STEM careers of K-12 students through Ohio State's TEK8 program.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.