sp Carbon chain interaction with silver nanoparticles probed by Surface Enhanced Raman Scattering

Abstract

Surface Enhanced Raman Spectroscopy (SERS) is exploited here to investigate the interaction of isolated sp carbon chains (polyynes) in a methanol solution with silver nanoparticles.Hydrogen-terminated polyynes show a strong interaction with silver colloids used as the SERS active medium revealing a chemical SERS effect. SERS spectra after mixing polyynes with silver colloids show a noticeable time evolution. Experimental results, supported by density functional theory (DFT) calculations of the Raman modes, allow us to investigate the behaviour and stability of polyynes of different lengths and the overall sp conversion towards sp 2 phase.

Surface-enhanced Raman scattering investigations of C2nH2 (n=4–6) in as-prepared and dried Ag colloid

“…To study the character of polyynes, surface-enhanced Raman scattering (SERS) is an effective way [2]. The vibrational features related to sp structures usually lay in the 1800-2200 cm −1 region [3], along with the G and D bands (1300-1600 cm −1 ), typical of amorphous sp 2 /sp 3 carbon materials [4].…”

Characteristic of silicon doped diamond like carbon thin films on surface properties and human serum albumin adsorption

“…In addition, it can be exploited to achieve a high sensitivity in detecting small amounts of sp carbon. [19] Raman spectra of DLC and related compounds showed a wide broad peak of carbon bands in the range of 1000-1750 cm -1 . The measured spectra employed two Gaussian peaks at 1349 cm -1 and 1538 cm -1 .…”

Carbon-atom wires: 1-D systems with tunable properties

“…Some strategies of this kind have been proposed so far. H-Terminated polyynes produced by submerged arc discharge in water show reduced stability, 86,112 while mixing the solution with silver colloids results in prolonged stability even in the solid state. In fact, by simply drying the solution one can obtain a solid sample (e.g., a thin film) consisting of an assembly of silver nanoparticles in which the wires display stability under ambient conditions for several weeks.…”

“…Hydrogen termination results in limited stability over time and the wires show transition towards sp 2 -carbon structures as a consequence of crosslinking reactions. 112 Bulkier endgroups provide higher stability to CAWs. For example, phenyl-endcapped polyynes (Ph-C n -Ph) up to n = 12 are stable under ambient conditions even in a solid film when the solvent is completely removed.…”