Abstract
Iridium oxide electrodeposited through a self-assembled colloidal template has an inverse opal structure. Monolayers present long range hexagonal arrangements of hemispherical nanocavities while multilayers present 3D honeycomb structures with spherical voids. The films are amorphous, have several electroactive redox states and are electrochromic. The nanostructure modifies their reflectivity thus indicating that these films could be used as tunable photonic devices.