Environmentally benign in situ synthesis of gold nanotapes using carboxymethyl cellulose.

An environmentally friendly one-step wet-chemical approach has been described for controlling the shape of gold nanocrystals at ambient temperature. In this approach, sodium salt of carboxymethyl cellulose (NaCMC) has been used as a reducing-cum-stabilizing agent for the in situ generation of gold nanotapes from an aqueous chloroaurate ion. Transmission electron microscopy confirmed the formation of tape-shaped gold nanostructures. These gold nanotapes exhibited interesting optical properties. The nature of crystallinity of the nanotapes has been studied by X-ray diffractometry. Control experiments with other cellulose derivatives resulted in the formation of only spherical gold nanoparticles.