2010: Oxidation of Filled Carbon Nanotubes inside a Transmission Electron Microscope

Introduction Filled (hybrid) carbon nanotubes (CNTs) have been studied intensively since 1993 [1], motivated by the prospect of using their inner chambers to synthesize novel crystals [2], to protect sensitive substances [3] or to tailor the properties of the host carbon shell or the guest material [4]. Recently, it was demonstrated that nanocable-like materials could be used as precursors for otherwise difficultto-produce nanostructures [5]. An example of a transition from a nanocable to a nanotube is provided by the controlled oxidation of turbostratic carbon nanotubes filled with Gadoped ZnS (a.k.a. Zn0.92Ga0.08S@CNT). Such studies of the reactivities of filled CNTs have usually been carried out using bench techniques. It is particularly challenging to characterize a single nanostructure throughout its life-cycle in a reactor. Even if such a study could be carried out, it may be affected by the transfer of the sample from a reactor to an analytical instrument (along with the danger of losing it). Thus, studies of the stability and reactivity of individual nanostructures should ideally be followed in analytical instruments that have in situ capabilities. In this communication, we show how an environmental transmission electron microscope can be used to follow the oxidation of an isolated filled carbon nanotube.