Variations in morphologies of silver nanoshells on silica spheres

In this report, three different silver nanoshell morphologies are produced on silica spheres using a simple, robust and rapid chemical method, without using added coupling agents or surface modifications of silica, leading to the formation of silica core–silver nanoshells with silica cores from 50 to 600 nm in diameter and silver shell morphologies ranging from continuous, uniform and smooth layer about 10 nm thick to rough surfaces of 3–5 nm nanoparticles to sharp spikes-like silver protrusions extending outward from the surface. We propose reaction mechanisms for the formation of the different silica–silver core–shell nanostructures.