Growth of Homogeneous High‐density Horizontal SWNT Arrays on Sapphire via a Magnesium‐assisted Catalyst Anchoring Strategy

In-situ growth of high-density single-walled carbon nanotube (SWNT) arrays with homogeneity is highly desirable for integrated circuits. However, disastrous migration and aggregation of catalyst nanoparticles on substrate has greatly limited the area of as-grown SWNT arrays. Herein, we develop a magnesium-assisted catalyst anchoring strategy to restrain catalyst nanoparticles sintering on substrate. Magnesium modification ameliorates sapphire surface by high temperature solid reaction and thus provides a stronger metal-support interaction (SMSI). Hereby, we realize the direct growth of high-density SWNT arrays that fully cover an entire 10 x 10 mm 2 substrate with the local highest density of ~110 tubes mm -1 using iron as catalyst. This strategy was also proven universal when employing solid carbide catalysts.