Snapshot Hyperspectral Imaging (SHI) for Revealing Irreversible and Heterogeneous Plasmonic Processes
Snapshot Hyperspectral Imaging (SHI) for Revealing Irreversible and Heterogeneous Plasmonic Processes
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DOI：
10.1021/acs.jpcc.8b01398
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发表时间：
2018-03-29
影响因子：
3.7
通讯作者：
Link, Stephan
中科院分区：
文献类型：
--
作者：
Kirchner, Silke R.;Smith, Kyle W.;Link, Stephan
等离子体介导的过程提供了独特的机会，选择性的电化学，光化学和电化学。确定颗粒不均匀性的影响是一个未解决的问题，因为通常这样的过程引入不可逆的变化的纳米催化剂和/或它们的周围环境。挑战在于通过缓慢的串行方法来监测异质非平衡动态，这些方法是几乎所有具有合适空间和/或光谱分辨率的光谱采集方法所固有的。在这里，我们提出了一种新的计量，快照高光谱成像（SHI），有利于在原位读出的管透镜图像和一阶衍射图像的暗场散射从许多个人的等离子体纳米粒子，同时提取各自的光谱。消失波激发与超连续激光使信噪比大于100，时间分辨率仅为1 ms。类似于100同时光谱的发射实现了高度有序的纳米粒子阵列，产生0.21 nm/像素的光谱分辨率。此外，另一种暗场激发几何结构利用超连续谱激光器和反射物镜的组合用于偏振控制SHI。使用一个简化版本的SHI，我们暂时解决了毫秒级的时间尺度上的电化学表面氧化还原反应的多相动力学的许多单独的金纳米粒子同时。
Plasmon-mediated processes provide unique opportunities for selective photocatalysis, photovoltaics, and electro-chemistry. Determining the influence of particle heterogeneity is an unsolved problem because often such processes introduce irreversible changes to the nanocatalysts and/or their surroundings. The challenge lies in monitoring heterogeneous non equilibrium dynamics via the slow, serial methods that are intrinsic to almost all spectral acquisition methods with suitable spatial and/or spectral resolution. Here, we present a new metrology, snapshot hyperspectral imaging (SHI), that facilitates in situ readout of the tube lens image and first-order diffraction image of the dark-field scattering from many individual plasmonic nanoparticles to extract their respective spectra simultaneously. Evanescent wave excitation with a supercontinuum laser enabled signal-to-noise ratios greater than 100 with a time resolution of only 1 ms. Throughput of similar to 100 simultaneous spectra was achieved with a highly ordered nanoparticle array, yielding a spectral resolution of 0.21 nm/pixel. Additionally, an alternative dark-field excitation geometry utilized a combination of a supercontinuum laser and a reflecting objective for polarization controlled SHI. Using a simplified version of SHI, we temporally resolve on the millisecond time scale the heterogeneous kinetics of an electrochemical surface redox reaction for many individual gold nanoparticles simultaneously.