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

太阳能将二氧化碳和水转化为有用的化学品和燃料，可以提供一条实现可持续碳循环的途径，同时保持化工和运输行业的现有基础设施。有效利用太阳能打破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Gupta和Asthagiri正在努力了解催化剂表面结构和太阳能转移到二氧化碳分子之间的关系。我们的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，PIS正在培训研究生将实验和理论相结合，以解决重要的能源产生和转换问题。此外，PIs正在吸引K-12和本科水平的学生参与，作为扩大学生参与STEM职业生涯多样化努力的一部分。作为俄亥俄州立大学TEK8项目的一部分，研究生正在开发模块，以吸引K-12学生对STEM职业的兴趣。此外，作为俄亥俄州立大学暑期研究机会计划的一部分，人数不足的本科生正在被招募参加暑期研究。在化学部NSF化学催化项目的资助下，俄亥俄州立大学的古普塔博士和Asthagiri博士正在开发一个实验与理论相结合的项目，旨在从根本上了解铜氧化物的局部表面结构与二氧化碳分子的光激发之间的关系。铜氧化物薄膜是在超高真空(UHV)中以可控的方式生长的，允许引入各种缺陷(例如空位、铜氧化物薄膜化学计量比的变化和掺杂)。具有局部光照度的扫描隧道显微镜(STM)可提供光照前后表面的直接图像。密度泛函理论(DFT)计算有助于解释来自STM的图像和光谱，从而将局部氧化铜位的电子态与所产生的CO2光化学之间的关系联系起来。此外，DFT正被用于探索对铜氧化物薄膜的修饰，以增强二氧化碳的光活性；这些预测正在进行实验测试，目的是建立一个预测模型，为二氧化碳的光还原建立最佳的铜氧化物纳米结构。作为该项目的一部分，私人投资机构积极参与招募研究生和本科生研究中代表性不足的群体，并开发模块，通过俄亥俄州立大学的TEK8计划培养K-12学生对STEM职业生涯的兴趣。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.