Carbon nanocages templated by gold nanostructures

Summary form only given. Hollow nanocages are useful in many applications including catalyst support, batteries and drug delivery. Several systems have been pursued to produce nanocages, but for carbon, studied cages are mainly smaller ones, like fullerenes. Attempts to make larger carbon nanocages are more limited, resulting in foam-like structures with relatively thick walls or by methods that do not easily get controllable sizes. For applications of nanocages there are needs for methods that allow carbon cages to be fabricated with determined size and shape. Here, we report on a new method to grow large carbon cages, using gold nanoparticles on carbon nanotubes as templates (Figure 1). The experiments were done inside a TEM using a special in-situ holder, called TEMSTM, with movable electrical probes, allowing a detailed observation and control of the entire process. The cages were grown on the nanoparticles under electrical Joule heating and the gold were subsequently evaporated, leaving the cages intact. The templating gold nanoparticles could be made in different sizes allowing size adjustments of the resulting carbon nanocages. The obtained cages may have wide applications including drug delivery and hydrogen storage.