= Solution
Use a shaped <nickel> particle or <nanowire> as both \b[sacrificial template and reducing agent]. <gold> grows where <nickel> is consumed, allowing gold-coated particles, porous shells and, with suitable removal of the remaining <nickel>, hollow <gold> <nanostructures>. The original template controls the overall shape; the balance of dissolution, deposition and <diffusion> controls wall thickness and <porosity>.
A hollow product is not guaranteed simply by writing the reaction: deposition may seal a solid <nickel> core, whereas defects can maintain access to the interior and permit further replacement. Controlled composition and transport can give a progression from core–shell to porous or hollow structures. This is useful for high-surface-area <electrodes>, catalytic surfaces and plasmonic structures, while avoiding an electrical lead to every individual <nanoparticle>.
Back to article page
