Synthesis of nature polymer supported Au, Ag and Au-Ag nanoparticles in aqueous medium and catalytic activity towards 4-nitrophenol reduction

We presented the preparation of gold nanoparticles, silver nanoparticles and gold-silver bimetallic nanoparticles (Au-Ag) by hyaluronic acid (HA). Initially small gold or silver nanoparticles acted as seeds, which catalyzed the reduction of added metallic ion in the presence of HA to form individual nanoparticles and Au-Ag bimetallic nanoparticles. To investigate their catalytic performance, we investigated that two metal nanoparticles functioned as effective catalysis for the reduction of 4-nitrophenol in the presence of NaBH₄. The formation and catalytic activity of metal nanoparticles were characterized by UV-Visible-NIR spectrophotometer. Field emission scanning electron microscopy (FESEM) study revealed the morphology of these metal nanoparticles.