NaCl–H2O-assisted preparation of SrTiO3 nanoparticles by solid state reaction at low temperature

An environmentally friendly NaCl–H2O system was developed to synthesize monodisperse strontium titanate (SrTiO3) nanoparticles from commercially available raw materials (SrCO3 and rutile) by solid state reactions. The formation rate of SrTiO3 was accelerated by the addition of NaCl and water vapor. Single phase SrTiO3 was obtained by calcination at 700 °C for 2 h in water vapor (H2O flow rate of 2.0 mL/min) by the addition of 50 wt% NaCl, although 900 °C and 750 °C for 2 h were required to complete the reaction by calcinations in air and air by the addition of 50 wt% NaCl, respectively. The results demonstrate that both NaCl and H2O played vital roles to accelerate the formation of SrTiO3 nanoparticles at relatively low temperature. On the basis of experiments and analysis, a rational growth mechanism has been proposed and discussed.