Name: probing the structure and dynamics of interfacial water with scanning tunneling microscopy and spectroscopy
Uploaded: 2018-05-27T13:00:00
Description: Watch this Scientific Journal Video about Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy at JoVE.com

这项工作由国家自然科学基金授予号 2016YFA0300901 2016YFA0300903 和2017YFA0205003 在11634001、11290162/A040106 的资助下, 由全国重点研究 & 开发项目提供资金。Y.J. 承认国家科学基金对杰出青年学者和长江青年学者项目的支持。j.g. 承认国家博士后项目对创新人才的支持。

注: 实验是在 5 K 上吸附在 Au 支持的氯化钠 (001) 薄膜 (图 1a) 上的水分子, 并配有 Nanonis 电子控制器的超高真空 (特高压) 低温 STM。
1. 实验样品的制作
<ol><li>
清洁金 (111) 单晶
	<ol>
<li>将燃气线泵入 10-7毫巴的压力, 然后用 Ar 气体冲洗煤气线。把泵/冲洗循环三次。 注: 每个泵/冲洗周期约为30分钟。</li>
		<li>用 Ar 气体将?...

<ol>
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为了探讨吸附在固体表面上的水分子的内部结构、动力学和振动光谱学, 特别注意氢的自由度, 一些实验步骤至关重要, 这将是在以下各段中讨论。
在两个关键步骤的基础上实现了水分子的轨道成像。首先, 绝缘 NaCl 膜以电子方式将水从金基底上解耦, 其次通过端-水耦合的 STM 尖端的轨道浇口效应。要在 au (111) 基板上生长双层 NaCl 膜, 金 (111) 基板的温度应保持在 290 K 左右。当?...

水与固体材料表面的相互作用涉及各种表面反应过程, 如异质催化、photoconversion、电化学、腐蚀和润滑等。1,2,3一般而言, 研究界面水、光谱和衍射技术是常用的, 如红外和拉曼光谱、总和频率生成 (SFG)、X 射线衍射 (XRD)、核磁共振 (NMR)、中子散射4,5,6,7,8。然而, 这些方法受到空间分辨率、光谱展宽和平均效应的限制。
STM 是一种很有希望的技术来克服这些限制, 它结合了亚Ångström 空间分辨率, 原子操作和单键振动灵敏度9,10,11,12,13,14. 自本世纪初以来, STM 已广泛应用于研究固体表面水的结构和动态3,15,16,17, 18,19,20。另外, 基于 STM 的振动光谱学可以从二阶导数差分隧穿电导 (d2I/dV2) 中获得, 也称为非弹性电子隧穿光谱学 (我们)。然而, 解决内部结构,即H 键方向性, 获得可靠的水振动光谱学仍然是一个挑战。主要的困难在于水是一个接近壳的分子, 其前沿轨道远离 EF, 因此 STM 尖端的电子几乎无法隧道到水的分子共振状态, 导致信噪比差。分子成像和振动光谱学。
水吸附在 Au 支持的 NaCl (001) 薄膜提供了一个理想的系统进行原子尺度调查的 STM 与 Cl 终止尖端 (图 1a), 这是执行在 5 K 在超高真空 (特高压) 环境中的基本压力优于 8×10-11毫巴。一方面, 绝缘 NaCl 薄膜以电子方式将水分子从 Au 基体中分离出来, 从而保留了水的原生边界轨道, 延长了驻留在分子共振状态中的电子的寿命。另一方面, STM 尖端可以通过尖端-水耦合有效地调节水的前沿轨道向 EF , 特别是当尖端与 Cl 原子功能化时。这些关键步骤使高分辨率的轨道成像和水单体和簇的振动光谱。此外 , 由于负电荷的 Cl 尖端与水之间的强静电相互作用 , 水分子可以以良好的控制方式纵。
本报告分别在1和2节详细概述了样品的制备程序和 STM 调查的 Cl 终止尖端。在3节中, 我们描述了轨道成像技术, 它解决了水单体和聚丙烯的 O H 方向性。在4节中引入了尖端增强我们, 它允许在单键极限下检测水分子的振动模式, 并从氧-氢拉伸中的红移中确定高精度的 H 键合强度。水的频率。在5节中, 我们展示了如何通过控制尖端操作来构造和切换水聚丙烯。基于轨道成像、光谱学和操作技术, 可以进行同位素替代实验, 对界面水中质子的量子性质进行探测, 如量子隧穿和零点运动。

<table border="0" cellpadding="0" cellspacing="0" style="width:632px;" width="633">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Au(111) single crystal</td>
			<td style="width:131px;">MaTeck</td>
			<td style="width:119px;">NA</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">NaCl</td>
			<td style="width:131px;">Sigma Aldrich</td>
			<td align="right">450006</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Water, deuterium-depleted&#160;</td>
			<td style="width:131px;">Sigma Aldrich</td>
			<td align="right">195294</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Deuterium oxide&#160;</td>
			<td style="width:131px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">364312</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Sealed-off glass-UHV adapters</td>
			<td style="width:131px;">MDC vacuum products</td>
			<td align="right" style="width:119px;">46300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Diaphragm-sealed valve</td>
			<td style="width:131px;">any</td>
			<td style="width:119px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Bellows-sealed valve</td>
			<td style="width:131px;">any</td>
			<td style="width:119px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Leak valve</td>
			<td style="width:131px;">Kurt J. Lesker&#160;</td>
			<td style="width:119px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Scanning tunneling microscopy</td>
			<td style="width:131px;">CreaTec</td>
			<td style="width:119px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Electronic controller.</td>
			<td style="width:131px;">Nanonis&#160;</td>
			<td style="width:119px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tungsten wire</td>
			<td style="width:131px;">any</td>
			<td style="width:119px;"></td>
			<td>diameter:0.3 mm; purity: 99.95%</td>
		</tr>
	</tbody>
</table>

probing the structure and dynamics of interfacial water with scanning tunneling microscopy and spectroscopy

水/固体界面无处不在, 在许多环境、生物物理和技术过程中发挥着关键作用。在固体表面吸附的水分子的氢键 (H 键) 动力学的求解是水科学的基本问题, 由于氢的重量轻、体积小, 这仍然是一个巨大的挑战。扫描隧穿显微镜 (STM) 是一个有希望的工具, 以攻击这些问题, 由于其能力的亚Ångström 空间分辨率, 单键振动灵敏度, 原子/分子操作。所设计的实验系统包括一个 Cl 终止尖端和一个样本, 通过将水分子就地制备到 Au (111) 支持的 NaCl (001) 表面。绝缘 NaCl 膜以电子方式将水与金属基体分离, 从而保留了水分子的固有前沿轨道。Cl 尖端促进了单水分子的操作, 并通过尖端水耦合将水的轨道浇到费米水平 (EF) 附近。本文概述了 submolecular 分辨率成像、分子/原子操作和界面水单键振动光谱的详细方法。这些研究开辟了一个新的途径, 以调查在原子能规模的 H 保税系统。

图 1a阐释了 STM 实验设置的示意图。首先, 金 (111) 基板是清洁的溅射和退火周期在特高压室。清洁 Au (111) 样品显示22×√3重建表面, 其中表面的原子占据了结构和 fcc 的地方形成人字构造 (插入图 1b)。氯化钠在 Au (111) 基板上蒸发, 形成双层岛屿 (图 1b)。然后, 水分子在 A...

Watch this Scientific Journal Video about Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy at JoVE.com

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy

用扫描隧穿显微镜和光谱法探讨界面水的结构和动力学

在这里, 我们提出了一个协议, 以研究在原子尺度上的界面水的结构和动力学, 在 submolecular 分辨率成像, 分子操作, 和单键振动光谱学。

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Insights into the Interactions of Amino Acids and Peptides with Inorganic Materials Using Single-Molecule Force Spectroscopy

洞察氨基酸和多肽与无机材料的使用相互作用的单分子力谱

The interactions between proteins or peptides and inorganic materials lead to several interesting processes. For example, combining proteins with minerals ...

Synthesis and Structure Determination of &#181;-Conotoxin PIIIA Isomers with Different Disulfide Connectivities

Synthesis and Structure Determination of ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Âµ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities

Peptides with a high number of cysteines are usually influenced regarding the three-dimensional structure by their disulfide connectivity. It is thus ...

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

软聚聚硅氧烷-尿素弹性体在人工晶体中的应用

This study discusses a synthesis route for soft polysiloxane-based urea (PSU) elastomers for their applications as accommodating intraocular lenses ...

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics

利用密度泛函理论和力场分子动力学对多相水-金属催化剂接口进行多尺度采样

A significant number of heterogeneously-catalyzed chemical processes occur under liquid conditions, but simulating catalyst function under such conditions ...

Performing Spectroscopy on Plasmonic Nanoparticles with Transmission-Based Nomarski-Type Differential Interference Contrast Microscopy

基于传输的野武学型差分干涉对比显微镜对等离子体纳米粒子的光谱处理

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using ...

Probing Surface Electrochemical Activity of Nanomaterials using a Hybrid Atomic Force Microscope-Scanning Electrochemical Microscope (AFM-SECM)

Probing Surface Electrochemical Activity of Nanomaterials using a Hybrid Atomic Force Microscope-Scanning Electrochemical Microscope AFM-SECM

使用混合原子力显微镜扫描电化学显微镜（AFM-SECM）探测纳米材料的表面电化学活性

Scanning electrochemical microscopy (SECM) is used to measure the local electrochemical behavior of liquid/solid, liquid/gas and liquid/liquid interfaces. ...

Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package

使用 UMD 软件包分析 Ab Initio 分子动力学模拟中的熔体和流体

We have developed a Python-based open-source package to analyze the results stemming from ab initio molecular-dynamics simulations of fluids. The package ...

Atomic Force Microscopy Combined with Infrared Spectroscopy as a Tool to Probe Single Bacterium Chemistry

原子力显微镜与红外光谱相结合，作为探测单一细菌化学的工具

Atomic Force Microscopy-Infrared Spectroscopy (AFM-IR) is a novel combinatory technique, enabling simultaneous characterization of physical properties and ...

Preparation of Nanoparticles for ToF-SIMS and XPS Analysis

用于ToF-SIMS和XPS分析的纳米颗粒的制备

Nanoparticles have gained increasing attention in recent years due to their potential and application in different fields including medicine, cosmetics, ...