Agarose biopolymer coating on polyurethane sponge as host for catalytic silver metal nanoparticles

In the present research work, we prepared a biopolymer-coated open pores polyurethane sponge (OPPUS) as an easily separating substrate for catalytic silver metal nanoparticles. The surface of OPPUS was coated with an agarose (AG) biopolymer. The prepared AG-OPPUS was immersed in AgNO3 salt solution for the entrapment of the metal ions in the AG coating layer. This material was treated with strong reducing agent solution to reduce the metal ions to the metal nanoparticles (Ag-0). The successful synthesis of the material was confirmed through FESEM, XRD, EDX and XPS techniques. Ag/AG-OPPUS was utilized as catalyst in reducing different dyes and other nitroaromatic compounds by sodium borohydride. Kinetic studies for the said the catalytic reduction reactions were carried out. Ag/AG-OPPUS showed superior performance with a reaction rate constant of 0.752min(-1) for the 4-nitrophenol reduction reaction. Another important aspect of the current developed catalyst is its separation and recovery without much compromising on the catalytic activity and efficiency.