基本金属纳米粒子的电化学稳定性
Lei Tang1, Xiaoqian Li, Robert C Cammarata
1Arizona State University, Tempe, Arizona 85287-8706, USA.
Journal of the American Chemical Society
|July 31, 2010
概括
纳米金属腐蚀对于传感和催化是至关重要的. 这项研究开发了一个热力学框架和潜在-pH图,预测纳米颗粒低于4nm电化学溶解,而较大的氧化.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 纳米技术 纳米技术
背景情况:
- 纳米级固体的腐蚀影响传感和催化.
- 了解元素金属的电化学稳定性至关重要.
研究的目的:
- 介绍纳米尺度固体腐蚀的一般热力学分析.
- 为构建一个粒子大小依赖的电位-pH图.
- 建立一个框架来评估纳米金属的电化学稳定性.
主要方法:
- 基本金属的一般热力学分析.
- 构建粒子大小依赖的电位-pH图.
- 电化学扫描道显微镜 (电-STM) 用于Pt-黑粒子稳定性.
主要成果:
- 热力学分析预测了尺寸依赖的腐蚀行为.
- 颗粒直径小于4纳米的电化学溶解 (Pt → Pt(2+) + 2e−).
- 预计较大的白金颗粒 (> 4 nm) 会形成氧化物.
结论:
- 开发的热力学分析为评估纳米级元素金属稳定性提供了一般框架.
- 使用电-STM的实验结果证实了对纳米粒子的理论预测.
- 这种方法适用于电化学应用中的各种纳米级元素金属.
更多相关视频
相关概念视频
Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
Electrochemical Systems
Electrochemical systems provide a fascinating insight into the dynamic interplay of charged species within various phases. One notable example is the interaction between a membrane permeable to K⁺ ions but not to Cl⁻ ions, separating an aqueous KCl solution from pure water. As K⁺ ions diffuse through the membrane, they generate net charges on each phase, leading to a potential difference between them.Similarly, when a piece of Zn is immersed in an aqueous ZnSO₄ solution, the Zn metal, composed...
Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...


