A "green" two-step methodology to prepare biobased gold-chitosan nanocomposite films using chitosan and AuCl4- as a stabilizer and precursor, respectively, is reported. The biobased nanocomposites were prepared in situ by a wet chemical reduction method. Effects of hydrazine and l-ascorbic acid as different strength reducing agents on the characteristics of gold nanoparticles were observed. In addition, the performance of these nanocomposite films as catalytic materials was assessed. The relevance of this work underlies that the catalytic activity, conversion degree and order of the reaction of the 4-nitrophenol-sodium borohydride (4NP-NaBH4) reduction system depend on the size distribution, content and mainly to the location of gold nanoparticles in the nanocomposite films. Finally, the potential recyclability of these nanocomposite films as catalytic materials was studied.
Keywords: chitosan; films; gold nanoparticles; nanocomposite catalysts; nanocomposites.