SERS Observation of the Adsorption Behavior of O2, H2O, and SO2 on Silver Powder Surfaces at Nearly Real Environmental Conditions

1989 ◽  
Vol 43 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Hideyuki Matsuta ◽  
Kichinosuke Hirokawa

The interaction of O2, H2O, and SO2 on silver powder prepared from the reduction of AgNO3 by NaBH4 was studied by surface-enhanced Raman scattering (SERS) at room temperature. The presence of H2O of about 103 Pa and O2 of about 104-105 Pa was necessary for observation of SERS peaks of SO32− and SO42−. The superoxide ion O2- was observed under high partial pressure for O2 conditions. SERS peaks of atomic oxygen, superoxide ion O2-, SO32−, and SO42− disappeared on evacuation. SERS peaks of surface species such as Ag2O did not disappear on evacuation.

2005 ◽  
Vol 59 (11) ◽  
pp. 1305-1309 ◽  
Author(s):  
David A. Heaps ◽  
Peter R. Griffiths

Surface-enhanced Raman spectra (SERS) of molecules separated by gas chromatography (GC) were measured off-line by condensing the analyte on a moving, liquid-nitrogen-cooled ZnSe window on which a 5 nm layer of silver had been formed by physical vapor deposition. After the components that eluted from the chromatograph had been deposited, the substrate was allowed to warm up to room temperature and transferred to the focus of a Raman microspectrometer where the spectrum of each component was measured. Band intensities in the spectrum of 3 ng of caffeine prepared in this way were approximately the same as in the spectrum of bulk caffeine. By making some logical assumptions, it was shown that identifiable GC/SERS spectra of 30 pg of many molecules could be measured over a 300 cm−1 region in real-time and that if an optimized substrate were used the minimum identifiable quantity could be reduced to 1 pg or less.


CrystEngComm ◽  
2016 ◽  
Vol 18 (42) ◽  
pp. 8284-8290 ◽  
Author(s):  
Yu-Kuei Hsu ◽  
Zhong-Bo Chen ◽  
Yu-Chang Lin ◽  
Ying-Chu Chen ◽  
San-Yuan Chen ◽  
...  

1987 ◽  
Vol 111 ◽  
Author(s):  
Paul B. Dorain ◽  
Joseph E. Boggio

AbstractAg powder is activated by pulsing it with NO2 gas which forms fresh Ag microclusters. This powder is then exposed to subsequent pulses of C2H2 or CH3C2H (3.7% in N2 ). The surface enhanced Raman scattering (SERS) spectra show dramatic intensity variations due to rapid changes in adatom concentration. Normalization of these time-dependent SERS spectra to the background scattering intensity, which is proportional to the adatom concentration, provides spectra which represent adsorbate coverage if major surface reconstruction does not occur. The temporal development of the SERS spectra of C2H2 shows rapid degradation with no evidence for adsorbed species. In contrast, propyne reacts more slowly, as evidenced by the behavior of the intensity at 1980cm−1 due to adsorbed -C2-. The reactions observed are in accord with the models developed by Barteau and Madix[1] and Vohs, Carney, and Barteau[2]. Exposure to both alkynes results in the appearance of SERS active NO, an adsorbant not previously observed at room temperature. Ellipsometric measurements are consistent with the presence of a carbon overlayer, which may stabilize the NO and render the system inert to further chemical reaction.


RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74662-74669 ◽  
Author(s):  
Bo Lu ◽  
Fangyi Zhan ◽  
Guodong Gong ◽  
Yali Cao ◽  
Qiang Zhen ◽  
...  

Room-temperature mechanochemical synthesis of Ag/Ag homojunction assemblies giving giant surface electric field enhancement for SERS.


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