Facile Method To Synthesize Mesoporous Multimetal Oxides (ATiO3, A = Sr, Ba) with Large Specific Surface Areas and Crystalline Pore walls

A new strategy to synthesize mesoporous multimetal oxides such as SrTiO3 and BaTiO3 by using in situ inorganic pore-makers based on the evaporation-induced self-assembly (EISA) approach, was studied. Following solvent evaporation and calcination, the excess Sr precursor partly reacts to form multimetal oxides and partly turns into nanoscale grains (SrCO3) dispersed in the sample. Then, the mesostructure is obtained by the removal of carbonate with acid. Increasing the amount of one metal precursor leads to an increase in the dispersion of the other metal precursor in the dry gel. This enables the second metal precursor to completely react at low calcination temperatures, and this can result in a reduction in impurities caused by the second metal precursor. Transmission electron microscopy (TEM) images of MST-1.5 in Figure 1a indicate that the sample has wormlike channels. X-ray diffraction (XRD) patterns show that the MST-1, MST-1.5, and MST-2 samples belong to a SrTiO3 phase.