Synthesis and characterisation of CeO2 nanoparticles and rods

Without adding any surfactant, CeO₂ nanoparticles and nanorods are prepared by a very simple hydrothermal method. CeO₂ nanocrystals with different morphologies were synthesised simply by dropping ammonia into cerium nitrate [Ce(NO₃)₃·6H₂O] water solution at room temperature. The obtained samples were characterised by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-visible absorption spectroscopy. The results show that all samples are indexed to phase of CeO₂. The synthesised nanoparticles are spherical with a 10-30-nm diameter and the nanorods are 100-200-nm in length and 5-10-nm in diameter. The morphology of CeO₂ transforms from granular to rod-like with the ammonia concentration increasing from 0.5, 1 to 2 mol/l. The UV vis spectra exhibit a slight red shift because of increasing crystallite size.