A NOVEL SYNTHESIS METHOD FOR SILVER NANOPARTICLES USING MOLTEN epsilon-CAPROLACTAM AS SOLVENT AND REDUCING AGENT

摘要

precipitation-reduction synthesis method for silver nanoparticles (Ag NPs) was developed. Molten epsilon-caprolactam (CL) was used not only as solvent but also as reducing agent and stabilizer. At first, Ag2O NPs was prepared by precipitation reaction of silver nitrate (AgNO3) and sodium hydroxide (NaOH) using molten CL as solvent at 100 degrees C. Then, Ag2O NPs was in situ reduced into Ag NPs by molten CL at 120 degrees C. Techniques of X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to monitor the synthesis process. With the increase of reduction time, monodispersed Ag2O NPs (ca. 3.7 nm) were integrated and larger Ag NPs (10-90nm) were formed. Fourier transform infrared (FT-IR) results showed that the surface of Ag NPs was capped with about 0.9 wt.% of CL molecules. Surface enhanced Raman scattering (SERS) effect of Ag NPs was investigated using Rhodamine 6G as a probe molecule.