Ultraviolet irradiated ozone treatment of a metal catalyst for the large-scale synthesis of single-walled carbon nanotubes with small, uniform diameters

Large-scale synthesis of single-walled carbon nanotubes with small diameters and narrow distribution was performed using catalytic decomposition of C2H2 at 800 °C by introducing an ultraviolet irradiated ozone (UV-ozone) treatment on an as-prepared Fe-Mo/MgO catalyst (APC). The UV-ozone treatment effectively suppressed metal migration and the agglomeration of the Fe-Mo catalyst on the MgO support material at high temperature (800 °C). During UV-ozone treatment, active oxygen species were adsorbed onto the APC and generated hydroxyl groups. The hydroxyl groups prevented the formation of large catalytic metal nanoparticles at 800 °C by acting as a surfactant. We also investigated whether the Mo species prevented the metal sintering of iron species into the MgO lattice.