One-step fabrication of diamond microtubes: A proof of concept

Abstract

A one-step methodology for the synthesis of diamond microtubes is proposed. Starting from carbon fibre (CF) substrates, diamond microtube is grown by Microwave Plasma Enhanced Chemical Vapour Deposition (MW PE CVD). Thanks to the graphitic nature of the CF, the substrate decomposition process (etching) takes place at the same time as the diamond layer grows on the CF substrate surface. The balance between the diamond growth rate and the CF etching is the key to obtain self-supporting microtubes. In addition, the nanodiamond seeding pretreatment prior to MW PE CVD growth has been shown to play a main role in the process, adjusting the relationship between diamond growth and carbon etching. This work is a proof of concept of the diamond microtube fabrication, in which the formation process and morphology of the diamond microtubes are structurally evidenced by Scanning Electron Microscopy, while Raman spectroscopy and High-Resolution Transmission Electron Microscopy allow to demonstrate the diamond nature of the microtubes.