Electrochemical synthesis of aligned amorphous carbon nanotubes/TiO2 nanotubes heterostructured arrays and its field emission properties

Highly aligned amorphous carbon nanotubes/TiO2 nanotubes (a-CNTs/TiO2) arrays are synthesized by combining anodic oxidation and electrochemical deposition method. The amorphous carbon nanotubes (a-CNTs) arrays grow along the axis direction on the top of TiO2 nanotubes arrays owing to the high potential and the confined surface. The a-CNTs arrays are tightly connected with TiO2 nanotubes forming the heterostructured a-CNTs/TiO2 nanotubes arrays. Here, the novel hetero-architecture demonstrates a low turn-on field of 2.6Vμm−1 and a high current density of 14mAcm−2. The excellent field emission performance is attributed to the synergetic effects among aligned nanotubes arrays structure, high aspect ratio, desirable interface contact between a-CNTs and TiO2 nanotubes, and low work function.