Photochemical deposition of SERS active silver nanoparticles on silica gel

Silver nanoparticles with an average size of nearly ∼15±3 nm were deposited onto the commercial silica gel matrix using aqueous solution of silver(I) gelatin complex. Silver(I) gelatin impregnated solid silica gel matrix has been found to produce silver particles with UV-light. The photoproduced silver nanoparticles remained very active for a long time. The surface characterization of the particles with transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDAX) and thermal analysis corroborated the presence of silver nanoparticles on silica surfaces. The resulting silver nanoparticles could easily be leached out from silica gel into an aqueous phase for indirect characterization of the nanoparticles by UV-Vis spectrophotometry. Anchoring of silver nanoparticles on silica gel helped to obtain surface enhanced Raman scattering (SERS) spectra, which was otherwise not possible in solution phase. The solid matrix served as a better catalyst for nitrophenol reduction than the simple silver nanoparticles in aqueous phase.