当前位置: X-MOL 学术Sci. Rep. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The importance of plasmonic heating for the plasmon-driven photodimerization of 4-nitrothiophenol.
Scientific Reports ( IF 3.8 ) Pub Date : 2019-02-28 , DOI: 10.1038/s41598-019-38627-2
Radwan M Sarhan 1, 2 , Wouter Koopman 1 , Roman Schuetz 3 , Thomas Schmid 2, 4 , Ferenc Liebig 5 , Joachim Koetz 5 , Matias Bargheer 1, 6
Affiliation  

Metal nanoparticles form potent nanoreactors, driven by the optical generation of energetic electrons and nanoscale heat. The relative influence of these two factors on nanoscale chemistry is strongly debated. This article discusses the temperature dependence of the dimerization of 4-nitrothiophenol (4-NTP) into 4,4'-dimercaptoazobenzene (DMAB) adsorbed on gold nanoflowers by Surface-Enhanced Raman Scattering (SERS). Raman thermometry shows a significant optical heating of the particles. The ratio of the Stokes and the anti-Stokes Raman signal moreover demonstrates that the molecular temperature during the reaction rises beyond the average crystal lattice temperature of the plasmonic particles. The product bands have an even higher temperature than reactant bands, which suggests that the reaction proceeds preferentially at thermal hot spots. In addition, kinetic measurements of the reaction during external heating of the reaction environment yield a considerable rise of the reaction rate with temperature. Despite this significant heating effects, a comparison of SERS spectra recorded after heating the sample by an external heater to spectra recorded after prolonged illumination shows that the reaction is strictly photo-driven. While in both cases the temperature increase is comparable, the dimerization occurs only in the presence of light. Intensity dependent measurements at fixed temperatures confirm this finding.

中文翻译:

等离子体加热对于4-硝基硫代苯酚的等离激元驱动的光二聚化的重要性。

金属纳米粒子在高能电子的光学产生和纳米级热量的驱动下形成有效的纳米反应器。这两个因素对纳米级化学的相对影响引起了激烈的争论。本文讨论了通过表面增强拉曼散射(SERS)将4-硝基硫酚(4-NTP)二聚化为吸附在金纳米花上的4,4'-二巯基偶氮苯(DMAB)的温度依赖性。拉曼测温法显示出颗粒的显着光学加热。此外,斯托克斯和反斯托克斯拉曼信号的比率表明,反应期间的分子温度升高到超过等离激元粒子的平均晶格温度。产物带具有比反应物带更高的温度,这表明反应优选在热点上进行。另外,在反应环境的外部加热期间反应的动力学测量导致反应速率随温度显着提高。尽管有显着的加热效果,但将外部加热器加热样品后记录的SERS光谱与长时间照明后记录的光谱进行比较,表明该反应严格是由光驱动的。虽然在两种情况下温度升高是可比较的,但是二聚化仅在存在光的情况下发生。在固定温度下与强度有关的测量结果证实了这一发现。将外部加热器加热样品后记录的SERS光谱与长时间照明后记录的光谱进行比较,表明该反应严格是由光驱动的。虽然在两种情况下温度升高是可比较的,但是二聚化仅在存在光的情况下发生。在固定温度下与强度有关的测量结果证实了这一发现。将外部加热器加热样品后记录的SERS光谱与长时间照明后记录的光谱进行比较,表明该反应严格是由光驱动的。虽然在两种情况下温度升高是可比较的,但是二聚化仅在存在光的情况下发生。在固定温度下与强度有关的测量结果证实了这一发现。
更新日期:2019-02-28
down
wechat
bug