Behaviour of transition metals catalysts over laser-treated vanadium support surfaces in the decomposition of acetylene Original Research Article

Laser-treated vanadium plates having high surface area were used as catalyst support in carbon nanotube synthesis under catalytic vapour deposition (CVD) conditions. Catalytic activity of various transition metals such as Fe, Co, or Ni was compared in the decomposition of acetylene at 720 °C. Transmission and scanning electron microscopy (SEM) observations showed that there were significant differences between carbon deposits formed over the various transition metal catalysts. Carbon nanotubes with the best quality were obtained over the iron catalyst. The density is high and carbon nanotubes of small diameter (10–15 nm) are typical in this sample. While the carbon source was mainly converted to amorphous or fibre-like material over cobalt and nickel catalysts, vanadia-supported iron provided carbon nanotubes of well-graphitized walls.