Hollow Titania Spheres from Layered Precursor Deposition on Sacrificial Colloidal Core Particles

The preparation of monodisperse hollow titania spheres with defined diameter, wall thickness, and crystal phase by the layer-by-layer templating of colloid particles and subsequent calcination (see Figure) is reported. A major advantage associated with this type of colloid templating is that it can be conducted from any aqueous solution. Nanometer-level control over the sphere wall thickness is achieved by varying the number of layers deposited on the particles.