Ultrafast and Controllable Phase Evolution by Flash Joule Heating

Flash Joule heating (FJH), an advanced material synthesis technique, has been used for the production of high-quality carbon materials. Direct current discharge through the precursors by large capacitors has successfully converted carbon-based starting materials into bulk quantities of turbostratic graphene by the FJH process. However, the formation of other carbon allotropes, such as nanodiamonds and concentric carbon materials, as well as the covalent functionalization of different carbon allotropes by the FJH process, remains challenging. Here, we report the solvent-free FJH synthesis of three different fluorinated carbon allotropes: fluorinated nanodiamonds, fluorinated turbostratic graphene, and fluorinated concentric carbon. This is done by millisecond flashing of organic fluorine compounds and fluoride precursors. Spectroscopic analysis confirms the modification of the electronic states and the existence of various short-range and long-range orders in the different fluorinated carbon allotropes. The flashtime-dependent relationship is further demonstrated to control the phase evolution and product compositions.

Automated summary

Flash Joule heating (FJH) has been utilized to synthesize different fluorinated carbon allotropes including fluorinated nanodiamonds, fluorinated turbostratic graphene, and fluorinated concentric carbon in a solvent-free manner. The modification of electronic states and the presence of various short-range and long-range orders in these fluorinated carbon allotropes have been confirmed through spectroscopic analysis. The relationship between flash time and phase evolution as well as product compositions has been further demonstrated.