OP: Surface- and Coherence-Enhanced Raman Sensing on MoS2 Heterogeneous Catalysts

在化学系化学测量与成像项目和材料研究系陶瓷项目的支持下，贝勒大学的张教授和德克萨斯农工大学的Sokolov和Voronine教授正在应用各种拉曼技术来监测半导体衬底上的加氢脱硫反应。加氢脱硫是一种广泛应用于天然气和成品油脱硫的催化化学工艺。了解它是如何在催化基质上发生的，将有助于提高炼油效率，减少对环境的影响。传统的等离子体拉曼技术被用来研究贵金属（金、银和铜）上的这些反应。虽然这些贵金属很重要，但研究非金属催化底物上的反应的能力是必要的。张教授、Sokolov教授和Voronine教授正在使用最先进的拉曼光谱技术来检测非金属衬底上的反应，如二硫化钼（MoS2）。他们正在开发的方法有可能在炼油厂研究以外的许多领域得到广泛应用。例如，开发的技术可用于监测环境分析中的污染物或破译DNA序列。三位教授还积极参与了许多外展活动，通过校园“物理日”活动、年度扫描隧道显微镜（STM）培训课程和本科生研究经验（REU）计划，将纳米平面学研究的激动人心的世界带给本科生和公众。贝勒大学的张教授、德克萨斯农机大学的Sokolov教授和Voronine教授正在利用最先进的拉曼光谱技术，推进非传统拉曼散射材料（如MoS2，一种重要的非均相催化材料）分子的分子水平化学鉴定。他们正在进行三个子项目a)研究二维（2D）半导体表面增强拉曼光谱（SERS）的起源；b)通过结合SERS表面增强和飞秒自适应光谱技术相干反斯托克斯拉曼散射（FAST CARS）相干增强，在二维材料上实现前所未有的拉曼信号增强；c)利用尖端增强拉曼光谱（TERS）以亚单层灵敏度和纳米尺度空间分辨率识别试剂、中间体和产品的化学成分。他们的工作重点是在分子水平上理解非金属纳米结构中拉曼信号增强的化学和物理性质。他们研究的预期结果包括更好地理解半导体中的结构-功能关系，从而设计出具有改进功能的先进材料。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and the Ceramics Program in the Division of Materials Research, Professor Zhang at Baylor University and Professors Sokolov and Voronine at Texas A&M University are applying various Raman techniques to monitor hydrodesulfurization reactions on a semiconductor substrate. Hydrodesulfurization is a catalytic chemical process widely used to remove sulfur from natural gas and from refined petroleum products. Understanding how it happens on a catalytic substrate will help to improve oil refining efficiency and reduce environmental impacts. Traditional plasmonic Raman techniques are used to study these reactions on noble metals (gold, silver, and copper). Although these noble metals are important, the ability to study reactions on non-metallic catalytic substrates is needed. Professors Zhang, Sokolov and Voronine are using the most advanced state-of-the-art Raman spectroscopic techniques to examine reactions on non-metallic substrates, such as molybdenum disulfide (MoS2). The methods they are developing have the potential to lead to broad applications in many areas other than oil refinery studies. For example, the developed techniques could be used to monitor pollutants in environmental analysis or decipher DNA sequences. Three professors are also actively involved in many outreach activities by bringing the exciting world of nanoplamonics research to undergraduate students and to the general public through the programs such as the "Physics Day" event on campus, annual scanning tunneling microscopy (STM) training sessions, and the Research Experiences for Undergraduates (REU) program. Professor Zhang at Baylor University, Professors Sokolov and Voronine at Texas A&M University are advancing molecular-level chemical identification of molecules on non-traditional Raman scattering materials, such as MoS2, an important material for heterogeneous catalysis, using a combination of the most advanced Raman spectroscopies. They are working on three subprojects a) to examine the origin of Surface-Enhanced Raman Spectroscopy (SERS) on the two-dimensional (2D) semiconductor; b) to achieve unprecedented Raman signal enhancement on the 2D materials via a combination of the surface enhancement of SERS and the coherence enhancement of Femtosecond Adaptive Spectroscopic Technique for Coherent Anti-Stokes Raman Scattering (FAST CARS); and c) to identify the chemical composition of reagents, intermediates, and products with submonolayer sensitivity and nanoscale spatial resolution using Tip-Enhanced Raman Spectroscopy (TERS). Their work focuses on the molecular-level approach to understanding the chemical and physical nature of the Raman signal enhancement in non-metallic nanostructures. The expected outcomes of their research include better understanding of the structure-function relationships in semiconductors for new designs of advanced materials with improved functionalities.