Self-Assembled Plasmonic Nanoparticles on Vertically Aligned Carbon Nanotube Electrodes via Thermal Evaporation

다국어 초록 (Multilingual Abstract)

<P>This study details the development of a large-area, three-dimensional (3D), plasmonic integrated electrode (PIE) system. Vertically aligned multiwalled carbon nanotube (VA-MWNT) electrodes are grown and populated with self-assembling silver nanoparticles via thermal evaporation. Due to the geometric and surface characteristics of VA-MWNTs, evaporated silver atoms form nanoparticles approximately 15–20 nm in diameter. The nanoparticles are well distributed on VA-MWNTs, with a 5–10 nm gap between particles. The size and gap of the self-assembled plasmonic nanoparticles is dependent upon both the length of the MWNT and the thickness of the evaporated silver. The wetting properties of water of the VA-MWNT electrodes change from hydrophilic (∼70°) to hydrophobic (∼120°) as a result of the evaporated silver. This effect is particularly pronounced on the VA-MWNT electrodes with a length of 1 μm, where the contact angle is altered from an initial 8° to 124°. Based on UV–visible spectroscopic analysis, plasmonic resonance of the PIE systems occurs at a wavelength of approximately 400 nm. The optical behavior was found to vary as a function of MWNT length, with the exception of MWNT with a length of 1 μm. Using our PIE systems, we were able to obtain clear surface-enhanced Raman scattering (SERS) spectra with a detection limit of ∼10 nM and an enhancement factor of ∼10<SUP>6</SUP>. This PIE system shows promise for use as a novel electrode system in next-generation optoelectronics such as photovoltaics, light-emitting diodes, and solar water splitting.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-22/am505999e/production/images/medium/am-2014-05999e_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am505999e'>ACS Electronic Supporting Info</A></P>