用光电子光谱学研究圆柱形和平面液体喷流的水性酸
Tamires Gallo1,2, Georgia Michailoudi3, Joana Valerio4
1Synchrotron Radiation Research, Lund University, Box 118, SE-22100 Lund, Sweden.
The journal of physical chemistry. B
|July 8, 2024
概括
同步辐射光电子光谱学揭示了氨 (NH4+) 和酸盐 (NO3-) 电离的差异. 的1s光辐射显示出比酸盐更高的异构性,表明水溶液中的电子特性不同.
科学领域:
- 物理化学 物理化学
- 表面科学是一门学科.
- 频谱学是一种光谱学.
背景情况:
- 酸溶液在各种工业和环境过程中至关重要.
- 了解水溶液中离子的表面行为对于化学和物理过程至关重要.
- 基于同步射辐射的光电子谱学为探测液体电子结构提供了强大的工具.
研究的目的:
- 在水溶液中研究氨 (NH4+) 和 (NO3-) 离子的电子特性和表面分布.
- 确定从NH4+和NO3-. 的N1s电子的光电离异性 (β参数).
- 探索光电子信号的光子能量依赖性和这些离子的表面分布.
主要方法:
- 利用基于同步射辐射的光电子光谱学,使用圆柱形微喷气和平喷气喷嘴.
- 测量了90°和魔力角度 (54.7°) 的电子发射,相对于极化.
- 采用SESSA模拟进行背景正常化,并分析β参数作为光子能量 (470-530 eV) 的函数.
主要成果:
- 获得了NH4+和NO3-的N1s电离的β参数值,NH4+显示的值高于≈0.1.1.
- 对NO3信号观察到光子能量依赖的截面变化,但对NH4+则没有.
- 发现NH4+与NO3的峰值面积比率与起飞角度保持不变,无论喷嘴类型如何.
结论:
- 这项研究提供了关于水溶液中NH4+和NO3-离子独特的光离子化动态的见解.
- 结果表明,和酸盐离子在溶液表面区域的分布类似.
- 这些发现有助于更好地理解使用先进的光谱技术在液体表面的离子行为.
相关概念视频
Atomic Absorption Spectroscopy: Atomization Methods
395
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
395
Atomic Spectroscopy: Absorption, Emission, and Fluorescence
854
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
854
Atomic Emission Spectroscopy: Instrumentation
359
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
359
Atomic Fluorescence Spectroscopy
274
Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which...
274
Atomic Emission Spectroscopy: Lab
155
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
155
Atomic Absorption Spectroscopy: Lab
329
For AAS measurements, samples must be introduced as clear solutions, often requiring extensive preliminary treatment to dissolve materials like soils, animal tissues, and minerals. Common methods for sample preparation include treatment with hot mineral acids, wet ashing, combustion in closed containers, high-temperature ashing, or fusion with reagents.
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...
329


