Synthesis and characterization of Ca3Co4O9 nanoparticles by citrate sol-gel method

A sol-gel method has been applied to synthesize Ca3Co4O9 powders by using calcium and cobalt nitrates as raw materials and citric acid as complexing agent. The Pyrolytic decomposition mechanism of the dried gel and formation process of Ca3Co4O9 were investigated by TG-DTA, XRD, FT-IR, SEM and TEM. The results show pure Ca3Co4O9 powders can be prepared after the dried gel was calcined at 750–900 °C for 2 h. 2% of polyethylene glycol (PEG) 400 as a dispersant was added to the nitrate solution during the formation of sol precursor. Ca3Co4O9 nanoparticles with a size of 30–50 nm can be obtained by the dried gel synthesized in the presence of PEG 400 calcined at 800 °C for 2 h.