[AgBr colloids prepared by electrolysis and their SERS activity research].

Ivory-white AgBr colloids were prepared by means of electrolysis. Two silver rods 1.0 cm in diameter and 10.

[Nano-silver colloids prepared by electrolysis and research on its SERS activity].

Three kinds of nano-silver colloids have been prepared by electrolysis of silver rod using sodium citrate solution and AgNO3 mixed with polyvinyl alcohol solution as electrolyte and applying 7 V direct current for one hour. Nano-silver colloids have been investigated by means of TEM, absorption spectrum, electrophoresis experiment and SERS. The particle size ranges roughly from 20 nm to 25 nm (spheroid) for sample 1, from 20 nm to 35 nm (spheroid) for sample 2, and from 30 to 80 (many-sided) for sample 3, featuring absorption maximum at 404, 421 and 434 nm, respectively.

[SERS of positive silver colloids with addition of aggregating agent].

A very strong surface-enhanced Raman scattering (SERS) spectrum was obtained when adding some aggregating agent such as HNO3 and NaNO3 in positive silver colloid reduced by citrate using 633 nm radiation. In aid of characterizing the SERS of this process, SERS from positive silver colloid with the addition of H2SO3, HCl, and NH3 recorded. It was found that the SERS come from the citrate when adding HNO3, NaNO3 and H2 SO3, from NH3 and citrate when adding NH3, and only from Ag-Cl when adding HCl through comparing the spectra.

[The SERS of glycine anhydride on positive silver colloids].

The Raman spectrum and SERS of glycine anhydride in acidic and basic media on positive silver colloids were recorded. Calculations of the vibration frequencies were performed for glycine anhydride by B3LYP at 6-31g(d) level. The assignment of Raman spectrum and SERS of glycine anhydride in acidic media were obtained with the help of calculation.

[Raman spectroscopic study of Ming Dynasty bar-tile from Heijing of Lufeng].

Ming dynasty bar-tile from the archaeological site of Heijing (Lufeng of Yunnan Province, China) was analyzed by Raman microscopy, X-ray diffraction and electron probe microscopy (EPMA). It was found that the major components of the tile are SiO2, besides moonstone(KAlSi3O8 var. of K-orthoclase), Na-orthoclase(NaAlSi3 O8 )and an unknown mineral (Al, Fe)3(PO4,VO4)2(OH)3.

[The enhanced mechanism of Cl- to SERS in silver colloid].

The SERS is enhanced when KCl is added to silver colloid and cation molecule. The hypothesis supposed that Cl- bridged between nano-silver and molecule, as a result the molecule adsorbing on nano-silver surface is promoted and the SERS is therefore enhanced. The CN- and NH3 can be better adsorbed when they are added separately to the nano-silver particles, Cl- and anion molecule.