In situ preparation of film and hydrogel bio-nanocomposites of chitosan/fluorescein-copper with catalytic activity.

Copper nanoparticles were introduced into chitosan/fluorescein (Ch/f) film and hydrogel matrices by immersion of the respective matrix into an aqueous solution containing the precursor metallic salt and further reduction in aqueous medium at 75°C for 3h under nitrogen (N) atmosphere. TGA was used to estimate the metallic content of Ch/f-Cu film and hydrogel nanocomposites. The prepared nanocomposites were proven to be effective as catalytic materials in the reduction of methylene blue (MB) employing NH as reducing agent. In addition, rate constants of the reduction reaction using Ch/f-Cu film and hydrogel nanocomposites as catalysts were determined. The experimental results showed that the catalytic activity and order of reaction of the MB-NH reduction system depended strongly on the type of nanocomposite used. Finally, the recyclability of the film and hydrogel nanocomposites as catalytic materials was also studied.