Collaborative Research: In Situ Surface Spectroscopy of 2D Material-based Electrocatalysis and Photoelectrocatalysis

电化学和光电电化学过程在广泛的能源相关和环境应用中具有重要意义，包括太阳能储存和碳修复。光电化学制氢尤其令人兴奋，因为它具有将太阳能转化为无碳化学燃料的潜力。该项目将通过研究对燃料和化学品的可持续生产至关重要的一类超薄催化材料中发生的基本物理和化学过程，提高光电催化反应的效率。该研究将利用各种形式的原位线性、非线性和超快光谱来研究二维二硫化物材料中的电催化（EC）和光催化（PEC），以表征EC/PEC反应中的三个关键因素：在EC和PEC过程中产生的界面静电（局部（即表面）静电场）、界面动力学和静电（光激发载流子动力学）以及界面分子结构（表面结合的中间物质）。和频产生（SFG）、二次谐波产生（SHG）、振动斯塔克位移（VSS）光谱和瞬态吸收光谱（TAS）将被用来揭示EC和PEC过程的关键机制信息，主要是将二氧化碳还原为甲醇和一氧化碳。光谱数据将作为电化学电位和电解质组成的函数在现场获得，并与产物收率和选择性相关。该项目包括以研究为基础的教育和推广活动，以促进学生参与科学、技术、工程和数学（STEM）学科。这些活动包括为高中科学教师举办的讲习班，旨在改善对有前途的高中生的教育，并鼓励他们对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。

Electrochemical and photoelectrochemical processes are important to a wide range of energy-related and environmental applications, including solar energy storage and carbon remediation. Photoelectrochemical hydrogen production is especially exciting for its potential to convert solar energy into carbon-free chemical fuels. The project will enable increased efficiency of photoelectrocatalytic reactions through study of the fundamental physical and chemical processes occurring in a class of ultrathin catalytic materials important for the sustainable production of fuels and chemicals.The study will investigate electrocatalysis (EC) and photoeletrocatalysis (PEC) in two-dimensional dichalcogenide materials using various forms of in situ linear, nonlinear, and ultrafast spectroscopy to characterize three critical factors in EC/PEC reactions: interfacial electrostatics (local (i.e., surface) electrostatic fields), interfacial dynamics and electrostatics (photoexcited charge carrier dynamics), and interfacial molecular structures (surface bound intermediate species) produced during the EC and PEC processes. Sum frequency generation (SFG), second harmonic generation (SHG), vibrational Stark Shift (VSS) spectroscopy, and transient absorption spectroscopy (TAS) will be employed to reveal key mechanistic information regarding the EC and PEC processes primarily for the reduction of CO2 to methanol and carbon monoxide. Spectroscopic data will be acquired in situ as a function of the electrochemical potential and electrolyte composition, and correlated with product yield and selectivity. The project includes educational and outreach activities that build upon the research to promote engagement of students in science, technology, engineering and mathematics (STEM) disciplines. These activities, which include workshop for high school science teachers, are directed at improving the education of promising high school students and encouraging their interest in STEM careers.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.