Advancing Soft X-ray Spectromicroscopy

未来 5 年，我们的研究将增强两种软 X 射线显微镜技术（扫描透射 X 射线显微镜 (STXM) 和叠层照相术）的仪器、技术和分析软件。我们将 (i) 提高空间分辨率； (ii) 提供更准确的二维空间分辨化学图谱 (iii) 设计方法以尽量减少辐射损伤，包括低温冷却和压缩传感（一种新颖的图像采集方法）。我们将利用这些改进的能力来研究（a）工作条件下二氧化碳电还原的催化剂（operando）； (b) 趋磁细菌对单晶磁铁矿的细胞内生物矿化机制，以及 (c) 耦合全球硫和碳循环的同生海洋细菌-古菌群落 S 1s 边缘的硫形态形成。 我们的长期目标是开发新的或改进的软 X 射线显微镜技术以及新的应用类别。在接下来的5年里，我们将：（1）在加拿大光源（CLS）和法国Synchrotron Soleil完成叠层成像技术（一种增强STXM空间分辨率的方法）的开发； (2)开展CO2电还原催化剂的原位和操作电化学STXM研究； (3) 在 2021 年秋季安装新的单色仪后，帮助重新调试 CLS 软 X 射线显微镜光束线，这将使 2000 年 3500 eV 能量范围内的性能提高一个数量级以上。 （4）利用新仪器开展生物地球化学研究，特别是利用S 1s边缘（2460 eV）分析与气候变化相关的系统中的硫形态。 从科学角度讲，该研究计划将为能源材料领域提供重要的新知识。我们将为二氧化碳电还原（一种回收二氧化碳的方法）提供新型催化剂的直接化学表征。在生物领域，我们将提供有关趋磁细菌对细胞内磁铁矿生物矿化的更多信息，以及新发现的原生生物物种（发现的第一个产生细胞内磁铁矿链的真核细胞）。这项研究中开发的改进的 STXM 和叠层记录功能将影响许多加拿大和国际研究人员的研究，特别是那些希望超越静态样品的成像和光谱，研究系统如何在温度、湿度、电流、化学反应等因素的影响下发生变化的研究人员。我们的仪器和技术开发将在 CLS 上发表在出版物和会议上，并通过 aXis2000（我开发并继续改进的光谱显微镜软件包）提供。通过解决挑战当前软 X 射线显微镜能力的具体项目，我的小组的研究极大地推进了该领域的发展，并使 CLS 软 X 射线显微镜设施（加拿大用于此类研究的首要系统）保持在最前沿。

Over the next 5 years our research will enhance instrumentation, techniques and analysis software for two soft X-ray microscopy techniques - scanning transmission X-ray microscopy (STXM) and ptychography. We will (i) improve spatial resolution; (ii) provide more accurate spatially resolved chemical mapping in 2D (iii) devise methods to minimize radiation damage, including cryo-cooling and compressive sensing, a novel image acquisition method. We will use these improved capabilities to study (a) catalysts for CO2 electro-reduction under working conditions (operando); (b) mechanisms of intracellular biomineralization of single crystal magnetite by magnetotactic bacteria, and (c) sulfur speciation at the S 1s edge of syntropic marine bacterial-archae consortia which couple global sulfur and carbon cycles. Our long-term objectives are to develop new or improved soft x-ray microscopy techniques, and new classes of application. In the next 5 years we will: (1) complete development of ptychography (a method of enhancing spatial resolution in STXM) at the Canadian Light Source (CLS) and at Synchrotron Soleil in France; (2) carry out in situ and operando electrochemical STXM studies of CO2 electro-reduction catalysts; (3) help re-commission the CLS soft Xray microscopy beamline after a new monochromator is installed in fall 2021, which will give more than an order of magnitude improvement in performance at energies in the 2000 3500 eV range. (4) carry out bio-geo-chemical studies with the new instrumentation, in particular use the S 1s edge (2460 eV) to analyze sulfur speciation in systems relevant to climate change. Scientifically this research program will provide important new knowledge in the energy materials sector. We will provide direct chemical characterization of new catalysts for CO2 electro-reduction, a method of recycling CO2. In the biological arena we will provide additional information on biomineralization of intracellular magnetite by magnetotactic bacteria, and a newly discovered protist species (first eukaryotic cell found which makes chains of intracellular magnetite). The improved STXM and ptychographic capabilities developed in this research will impact studies by many Canadian and international researchers, in particular those who wish to go beyond imaging and spectroscopy of static samples, to studies of how systems change under the influence of factors such as temperature, humidity, electrical currents, chemical reactions etc. Our instrumentation and technique development will be made available at CLS presented in publications and conferences and through aXis2000, the spectromicroscopy software package that I developed and continue to improve. By tackling specific projects which challenge current soft X-ray microscopy capabilities, my group's research significantly advances the field, and keeps the CLS soft X-ray microscopy facility, Canada's premier system for such studies, at the forefront.