Metal oxide nanoparticles from inorganic sources via a simple and general method

A new, general, and simple method has been developed for the synthesis of metal oxide nanoparticles using generic chemicals. The method is based on the stabilizing of nanoparticles by capping their surface with organic ligands. ZrO2 nanoparticles with an average particle size of 13 nm were synthesized using zirconium nitrate or zirconium oxychloride as the source material. The method was further applied for preparation of Co3O4, mixed oxides ZrO2–Co3O4, ZrO2–NiO, and ZrO2–Co3O4–NiO. The metal oxides nanoparticles were highly crystalline and had a narrow particle-size distribution. XRD analysis of the zirconium oxide indicated that it was predominantly in the monoclinic phase, with a small fraction in the tetragonal phase. However, the phase of zirconia in the mixed oxides was a pure tetragonal one, owing to the existence of Ni and Co ions that could stabilize the metastable tetragonal phase.