Template-free, hollow and porous platinum nanotubes derived from tobamovirus and their three-dimensional structure at the nanoscale

We describe a simple method for the production of hollow, porous and template-free thick-walled platinum nanotubes. The external surface of a tobamovirus was mineralized via a wet chemical process to generate a uniform and dense platinum nanoparticle layer. The virus template was subsequently removed using a controlled annealing process in air. The morphology of the platinum nanotubes was studied using a range of characterization techniques that show it to be free of biological template and consisting of domains of crystalline platinum metal. High-resolution 3D-TEM tomography revealed that the platinum nanotubes contained a central hollow channel of diameter similar to 13 nm running along their lengths and showed the metallic layer to be porous with voids of sizes up to 10 nm. This method for production of hollow tubular nanostructures could be useful for production of bespoke platinum catalysts and may be adaptable to different metals and metal oxides for use in conductive, catalytic and sensor applications.