Cyanide-free preparation of gold nanowires: Controlled crystallinity, crystallographic orientation and enhanced field emission

The environmentally friendly preparation of nanomaterials with controlled structural features represents a development trend of nanoscience and nanotechnology. In this work, using a cyanide-free bath, gold nanowires with controlled crystallinity and preferred crystallographic orientation have been prepared by electrochemical deposition in home-made polycarbonate ion track-etched templates. Single-crystal and polycrystal gold nanowires with preferred orientations along the [111] and [100] directions have been obtained by selecting fabrication parameters. The influence mechanisms of nanopore diameter, applied voltage, and deposition temperature on structural properties are proposed. In addition, single-crystal nanowires with [100] preferred orientation show enhanced field emission, which may be attributed to their single-crystal structure and the lower work function of loosely packed crystal planes.