Highly efficient carbon nanotube growth on plasma pretreated stainless steel substrates

We present here the direct growth of carbon nanotubes (CNT) on austenitic stainless steel (SUS316L) sheets containing catalytic elements that enable repeated growth without extra deposition of buffer and catalytic layers. We compared the effects of substrate pretreatment methods consisting of a combination of air-annealing and Ar-plasma treatment. The air-annealing and plasma-treatments were performed using a thermal furnace and cylindrical plasma chamber to induce morphological changes in the substrate surface. The roughness of the substrates was found to be considerably altered by annealing temperature, plasma pretreatment temperature, and growth temperature. The highest CNT height of 23.5 μm was obtained using SUS316L samples that were plasma-treated and air-annealed at 725 °C. Finally, the CNT growth efficiency was found to be enhanced considerably by the substrate pretreatments.