Microstructural investigations on zirconium oxide–carbon nanotube composites synthesized by hydrothermal crystallization Original Research Article

Zirconium oxide (ZrO2)/carbon nanotube composites were prepared by hydrothermal crystallization at 200 °C for 8 h of zirconium hydroxide [(Zr(OH)4nH2O; n=8–16] in the presence of carbon nanotubes. The hydrothermal crystallization of zirconium oxide, under autoclave conditions, occurred on the walls of the tubes. The process yielded a homogeneous composite powder consisting of microcrystalline ZrO2 and multi-walled nanotubes, hence representing an alternative route for the synthesis of ceramic–nanotube composites. Microstructural and qualitative characterizations were performed using different electron microscopy techniques.