Yucca-derived synthesis of gold nanomaterial and their catalytic potential.

AuNPs ranging in 20 to 300 nm size were synthesized at a room temperature using Yucca filamentosa leaf extract. Diverse nanomaterial morphologies were obtained by varying the extract concentration, reaction pH, and temperature. While low volumes of extract (0.25 and 0.5 mL) induced the formation of microscale Au sheets with edge length greater than 1 μm, high volumes yielded spherical particles ranging from 20 to 200 nm. Varying pH of the solution significantly influenced the particle shape with the production of largely spherical particles at pH 5 to 6 and truncated triangles at pH 2. Separation of multidimensional nanostructures was achieved using a novel method of sucrose density gradient centrifugation. The catalytic function of Yucca-derived AuNPs was demonstrated by degradation of a wastewater dye: methylene blue using spectrophotometric measurements over time. Treatment with Au nanosheets and spheres demonstrated methylene blue degradation approximately 100% greater than the activity in control at 60 min.