Formation of Ag nanoparticles in PVA solution and catalytic activity of their electrospun PVA nanofibers

Ag nanoparticles (NPs) were prepared by chemical reduction based on green synthesis in an aqueous poly(vinyl alcohol) (PVA) solution with different temperatures and pHs. The PVA and maltose were used as stabilizing and reducing agents, respectively. Silver nitrate (AgNO3) precursor for Ag NPs was also used by 1 wt% on the base of the weight of PVA. The formation of Ag NPs was examined by UV-Vis spectrophotometer, and their size was measured by transmission electron microscopy (TEM), and nanoparticle size analyzer (NPSA). The formation rate of Ag NPs in the PVA solution increased with increasing temperature and pH, whereas the size of Ag NPs stabilized with PVA increased with increasing temperature, or with decreasing pH. Subsequently, the PVA nanofibrous matrix containing Ag NPs was prepared, by electrospinning PVA solution with Ag NPs, and followed by heat treatment. The morphology and crystalline structure of PVA nanofibers with Ag NPs was observed with field emission scanning electron microscopy (FE-SEM), and X-ray diffractometer (XRD), respectively. From the degradation reaction of methylene blue (MB) using PVA nanofibers web and film, it was found that the catalytic activity of PVA matrices with Ag NPs was strongly dependent on the surface area of the PVA matrices.