Facile synthesis of silver nanoparticles with high concentration via a CTAB-induced silver mirror reaction

Silver colloidal nanoparticles were synthesized via an analogous silver mirror reaction process without the traditional Tollens reagent. Instead of ammonia, cetyltrimethylammonium bromide (CTAB) was employed to coordinate with Ag+. The silver nanoparticles and reaction process were characterized by UV–vis spectrometer, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results showed that the silver concentration in the colloid reached 0.05 mol/l and the colloid could keep stable for over 45 days. The halogen in CTAB is used as surfactant counterion to form a CTABr−Ag+ complex, which can be reduced by glucose to Ag nanoparticles. Besides, the apparent impact on the dispersion and shape of silver nanoparticles induced by the molar ratio of CTAB to Ag is also discussed.