Influence of synthesis route on the morphology of SrTiO 3 particles

The cubic perovskite SrTiO 3 is an important semiconductor oxide with a band gap of 3.2 eV. It has a wide variety of applications such as: dielectric materials, photoluminescent devices, and in photocatalysis. It is conventionally obtained by the classic solid state synthesis (SS), in which TiO 2 and SrCO 3 react for several hours at temperatures as high as 1200 °C. Besides the high energy demand, SS is not useful for the control of physical characteristics, such as particle size and morphology, which has become essential for some of its applications. It is known that many soft and green routes can produce SrTiO 3 . Among them, the hydrothermal (HT) and sol-precipitation (SP) methods, as well as the molten salt synthesis (MS) are interesting not only due to their low cost and energy use, but also because of the possibility of particle size and shape control. This study compares the size and morphology of the SrTiO 3 particles obtained by these three synthetic pathways. Scanning electron microscopy (SEM) was used to compare particle size and morphology, and X-ray diffraction (XRD) was used to confirm the perovskite formation as well as to determine the Scherrer’s particle size.