Synthesis and characterization of hollow silver spheres at room temperature

Hollow silver spheres were synthesized at room temperature using sodium borohydride (NaBH4) as the reducing reagent and poly (vinyl pyrrolidone) (PVP) as the surfactant. The size of the synthesized hollow spheres ranged from 120 to 250 nm, and the surface was composed of many smaller silver nanoparticles. The asobtained product was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis absorption spectra. The amount of PVP had a significant effect on the morphology of the resultant silver samples. With an increasing concentration of PVP, the silver products possessed rod-like and shuttle-like shapes. The UV-vis spectrum demonstrated that the broad absorption peak centered at 417 nm resulted from the surface plasmon resonance (SPR) excitation of silver.