Chemical Requirement for Extracting Energetic Charge Carriers from Plasmonic Metal Nanoparticles to Perform Electron-Transfer Reactions
Chemical Requirement for Extracting Energetic Charge Carriers from Plasmonic Metal Nanoparticles to Perform Electron-Transfer Reactions
复制标题
从等离子体金属纳米颗粒中提取高能电荷载体以进行电子转移反应的化学要求
DOI：
10.1021/jacs.8b11949
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发表时间：
2019-01-09
影响因子：
15
通讯作者：
Linic, Suljo
中科院分区：
文献类型：
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作者：
Rao, Vishal Govind;Aslam, Umar;Linic, Suljo
在金属纳米颗粒上进行电子转移反应需要在纳米颗粒处分离电荷载体并将其转移到反应分子。使用光诱导这些反应是具有挑战性的，因为在光照射下在金属纳米颗粒中形成的高能电荷载流子的寿命极短。这里描述的结果表明，必须满足某些条件才能在等离子体纳米粒子上驱动这些电子转移反应。一个关键的要求是电子激发的过程发生在纳米颗粒/分子界面。这是通过在等离子体纳米颗粒的表面处的高等离子体电场来实现的。此外，从我们的研究中还可以明显看出，空穴（或电子）清除剂的电子（或空穴）供给能力需要足够高，以允许从纳米颗粒/分子复合物中提取空穴（或电子），从而完成催化循环。我们讨论了这些发现，通过一个案例研究的转化亚甲基蓝（MB）到一个减少MB离子自由基的表面上的等离子体银和银-铂核壳纳米粒子。为了直接监测MB在纳米颗粒表面上的还原反应，我们使用了随时间变化的原位表面增强拉曼散射测量，这也告诉我们等离子体激元驱动的电荷转移的基本机制细节。
Performing electron-transfer reactions on metal nano particles requires separation of charge carriers at the nanoparticle and their transfer to the reacting molecules. Inducing these reactions using light is challenging due to the exceedingly short lifetimes of energetic charge carriers formed in metal nanoparticles under light illumination. The results described here show that certain conditions must be met to drive these electron-transfer reactions on plasmonic nanoparticles. One critical requirement is that the process of electronic excitation takes place at the nanoparticle/molecule interface. This is accomplished by high plasmonic electric fields at the surface of plasmonic nanoparticles. Furthermore, it is also evident from our study that the electron (or hole)-donating capacity of the hole (or electron) scavengers needs to be high enough to allow for the extraction of holes (or electrons) from the nanoparticle/molecule complex, therefore completing the catalytic cycle. We discuss these findings through a case study of the conversion of methylene blue (MB) into a reduced MB ion radical on the surface of plasmonic Ag and Ag-Pt core shell nanoparticles. To directly monitor the reduction reaction of MB on the nanoparticle surfaces, we have used time-dependent in situ surface-enhanced Raman scattering measurement, which also informs us about the underlying mechanistic details of plasmon-driven charge transfer.