Spectroelectrochemistry of Halide Anion Adsorption and Dissolution of Single Gold Nanorods
Spectroelectrochemistry of Halide Anion Adsorption and Dissolution of Single Gold Nanorods
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DOI：
10.1021/acs.jpcc.6b00650
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发表时间：
2016-09-22
影响因子：
3.7
通讯作者：
Landes, Christy F.
中科院分区：
文献类型：
--
作者：
Hoener, Benjamin S.;Byers, Chad P.;Landes, Christy F.
光谱电化学流动池是用来探测本地化的表面等离子体共振（LSPR）的相同的单一的金纳米棒（金纳米棒）在氟化钠，氯化钠，溴化钠电解质，使用暗场散射显微镜。共振能量的变化，线宽（半高全宽，fwhm），和峰值强度的洛伦兹适合单个AuNR散射光谱的杆充电进行比较，以确定阴离子吸附的作用。我们证明，在正电位高达+0.25 V相对于铂准参比电极，诱导的变化在LSPR是独立的卤素阴离子。在更正的电位（+0.3至+0.35 V）溴离子和氯离子阻尼AuNR LSPR，观察到线宽的增加。在所有三种电解质溶液中研究的最正电位（+0.35V）下，AuNR散射强度在溴化物电解质中不可逆地降低，表明溶解。溴化物介导的溶解的动力学可以由电解质浓度控制，并且显示由于溶解引起的共振能量的变化随着从负电位到正电位的每个循环而增加。
A spectroelectrochemical flow cell is used to probe the localized surface plasmon resonance (LSPR) of the same single gold nanorods (AuNRs) in sodium fluoride, sodium chloride, and sodium bromide electrolytes using dark-field scattering microscopy. The changes in resonance energy, line width (full-width at half-maximum, fwhm), and peak intensity of a Lorentzian fit to single AuNR scattering spectra as the rods are charged are compared to determine the role of anion adsorption. We demonstrate that at positive potentials up to +0.25 V relative to a Pt quasi-reference electrode, the induced changes in the LSPR are independent of halide anion. At more positive potentials (+0.3 to +0.35 V) bromide and chloride ions damp the AuNR LSPR, observed as an increase in the line width. At the most positive potential investigated in all three electrolyte solutions (+0.35 V), the AuNR scattering intensity decreases irreversibly in bromide electrolyte, indicating dissolution. The kinetics of the bromide-mediated dissolution can be controlled by the electrolyte concentration and show that the change in resonance energy due to dissolution increases with each cycle from negative to positive potential.