Preparation of oriented gold plate/cellulose nanofiber composite films by using TEMPO-oxidized cellulose nanofiber as a reducing agent

TEMPO-oxidized cellulose nanofiber (TOCN) has been drawing much attention as a useful material for preparation of transparent and stiff films or substrates. In this work, reducing ability of TOCN was investigated in both photochemical and chemical synthesis of gold nanoparticles (AuNPs) from chloroauric acid (HAuCl4). Based on the results, AuNPs-TOCN composite films were prepared by heat drying the solutions containing only HAuCl4 and TOCN. Blue and yellow films were obtained depending on different contents of HAuCl4 and the yellow film showed high light reflection which was similar to gold film. X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements showed that gold plates were generated in the TOCN film, and their flat (1 1 1) crystal plane were oriented parallel to the film plane.