Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK.
Nanoscale. 2013 Jun 7;5(11):4884-93. doi: 10.1039/c3nr00898c. Epub 2013 Apr 25.
Analytical expressions for the anodic stripping voltammetry of metallic nanoparticles from an electrode are provided. First, for reversible electron transfer, two limits are studied: that of diffusionally independent nanoparticles and the regime where the diffusion layers originating from each particle overlap strongly. Second, an analytical expression for the voltammetric response under conditions of irreversible electron transfer kinetics is also derived. These equations demonstrate how the peak potential for the stripping process is expected to occur at values negative of the formal potential for the redox process in which the surface immobilised nanoparticles are oxidised to the corresponding metal cation in the solution phase. This work is further developed by considering the surface energies of the nanoparticles and its effect on the formal potential for the oxidation. The change in the formal potential is modelled in accordance with the equations provided by Plieth [J. Phys. Chem., 1982, 86, 3166-3170]. The new analytical expressions are used to investigate the stripping of silver nanoparticles from a glassy carbon electrode. The relative invariance of the stripping peak potential at low surface coverages of silver is shown to be directly related to the surface agglomeration of the nanoparticles.
提供了从电极上析出自金属纳米粒子的阳极溶出伏安法的解析表达式。首先，对于可逆电子转移，研究了两个极限：扩散独立纳米粒子的极限和每个粒子的扩散层强烈重叠的区域。其次，还推导出了在不可逆电子转移动力学条件下伏安响应的解析表达式。这些方程表明，在还原过程中，表面固定的纳米粒子被氧化为溶液相中相应的金属阳离子，剥离过程的峰电位预计将出现在比该氧化过程的形式电位更负的位置。通过考虑纳米粒子的表面能及其对氧化形式电位的影响，进一步发展了这项工作。根据 Plieth 提供的方程对形式电位的变化进行建模[J. Phys. Chem., 1982, 86, 3166-3170]。新的解析表达式用于研究从玻碳电极上剥离银纳米粒子。在银的低表面覆盖率下，剥离峰电位的相对不变性被证明与纳米粒子的表面团聚直接相关。
