Aguirre M E, Armanelli A, Perelstein G, Feldhoff A, Tolley A J, Grela M A
Departamento de Química, Universidad Nacional de Mar del Plata, Funes 3350, B7602AYL Mar del Plata, Argentina.
Nanoscale. 2015 Apr 21;7(15):6667-74. doi: 10.1039/c5nr00364d.
Plasmonic nanostructures comprising Au and ZnO nanoparticles synthesized by the spontaneous reduction of HAuCl4 in ethylene glycol were used to assess the possibility of modulating the direction of the electron transfer processes at the interface. One electron UV reduction and visible oxidation of the reversible couple TEMPOL/TEMPOL-H was confirmed by EPR spectroscopy. The apparent quantum yield for TEMPOL-H conversion under continuous wave visible excitation depends on the irradiation wavelength, being 0.57% and 0.27% at 450 ± 12 and 530 ± 12 nm, respectively. These results indicate that both the surface plasmon resonance and the interband transition from the 5d to the 6s level of Au nanoparticles contribute to the visible activity of the nanostructure. In addition, by detecting free electron conduction band electrons in ZnO, after the visible excitation of Au/ZnO nanostructures, we provide direct evidence of the photoexcited electron transfer from gold nanoparticles to ZnO.
通过在乙二醇中自发还原 HAuCl4 合成的包含金和氧化锌纳米颗粒的等离子体纳米结构，用于评估调节界面处电子转移过程方向的可能性。通过电子顺磁共振光谱证实了可逆偶联物 TEMPOL/TEMPOL-H 的单电子紫外还原和可见光氧化。在连续波可见光激发下，TEMPOL-H 转化的表观量子产率取决于照射波长，在 450 ± 12 和 530 ± 12 nm 处分别为 0.57% 和 0.27%。这些结果表明，表面等离子体共振以及金纳米颗粒从 5d 到 6s 能级的带间跃迁都有助于纳米结构的可见光活性。此外，通过检测氧化锌中的自由电子导带电子，在金/氧化锌纳米结构的可见光激发后，我们提供了光激发电子从金纳米颗粒转移到氧化锌的直接证据。
