Surface fabrication of hollow nanoarchitectures of ultrathin titania layers from assembled latex particles and tobacco mosaic viruses as templates

A novel procedure for fabricating nanoarchitectures of ultrathin titania layers was developed by using assembled latex particles and tobacco mosaic viruses (TMV) as templates. Latex particles and TMVs were assembled on the surface and then covered with ultrathin titania films by the surface sol-gel process. When the surface-covered latex template was subjected to an oxygen plasma treatment, hollow titania spheres connected with each other via nanotubes were formed at the original deposition of the particles. The titania-coated TMV produced tubular structures after the oxidative removal of the template. It is clear that the as-prepared titania shells replicated the original shape of the templates after its removal. The hollow structures were preserved despite the thickness of titania films being only a few nanometers. The use of oxygen plasma was indispensable for maintaining a three-dimensional structure because calcinations of the same sample gave flattened disks as a result of the collapse of the hollow shells.