Vertically aligned carbon nanotubes grown on Au/Ni films and the role of Au in the grown process

The vertically aligned carbon nanotubes(CNTs) were synthesized on Au/Ni catalyst films by plasma enhanced hot filament chemical vapor deposition(PE-HFCVD) method at 96% concentration of hydrogen. The growing process of CNTs on Au/Ni film was discussed. The realization of the vertically aligned CNTs grown at high hydrogen concentration can be attributed to the adoption of the Au/Ni catalyst films. The element Au promoted the diffusion of the carbon and improved the activity of carbon in catalyst. By comparing with the use of only Ni as catalyst, the Au in Au/Ni catalyst film can increase the carbon absorption, so carbon could be easily saturated in the catalyst and the vertically aligned CNTs were achieved at a high hydrogen concentration.