Why is an aluminium coat added before the catalyst for CNT growth by CVD?
It seems like a chemistry problem for the electronics market.

Role of subsurface diffusion and Ostwald ripening in catalyst formation for single-walled carbon nanotube forest growth.


  ... any Fe compounds spanning Fe salts, nanoparticles, and buckyferrocene could serve as catalysts for single-walled carbon nanotube (SWNT) forest growth when supported on AlO(x) and annealed in hydrogen. This observation was explained by subsurface diffusion of Fe atoms into the AlO(x) support induced by hydrogen annealing where most of the deposited Fe left the surface and the remaining Fe atoms reconfigured into small nanoparticles suitable for SWNT



Ref: https://www.researchgate.net/publication/221736532_Role_of_Subsurface_Diffusion_and_Ostwald_Ripening_in_Catalyst_Formation_for_Single-Walled_Carbon_Nanotube_Forest_Growth

Other: https://www.nature.com/articles/s41598-017-10055-0

They still haven't figured out how to attach electrodes very well without damaging the forest.