Inverse precipitation synthesis of ZrO2 nanopowder and in-situ coating on MWCNTs

ZrO2-multiwall carbon nanotubes composite was successfully prepared by simple inverse precipitation method. The effects of initial ZrOCl2·H2O concentration (0.5 and 1 g) and stirring speeds (400, 800 and 1200 rpm) on the phase formation, texture, surface characterization and microstructural evolutions were studied. Results from XRD showed that almost all of the synthesis ZrO2 exists in tetragonal phase; however, depending on ZrOCl2·8H2O concentration and stirring speed, some peaks of monoclinic phase existed in the composites. Texture studies illustrated the (111) plane preferred growth for tetragonal phases. The FTIR results confirmed the formation of different oxide groups in the surface of the CNTs. In addition, formation of the tetragonal ZrO2 on the surface of CNTs was proved by Raman spectroscopic analyses. The results from microscopic images showed that the size of the ZrO2 nanoparticles significantly decreased (30 nm) with an increase in the initial ZrOCl2·8H2O concentration to 1 g.