Synthesis of ceramic powders by using lamellar silica as precursor

In this work, it is shown that, by using lamellar silica samples and metal chlorides as precursors, homogeneous ceramic powders of the type SiO2–MO, with M=Zn, Mn, Ni and Co, can be synthesized. The powders were obtained by dispersion of 2.0 g of lamellar silica powders in 200 cm3 of a 0.5 mol dm−3 solution of the respective metal chloride, followed by filtration and calcination at 600°C for 30 min in an oxidizing atmosphere. As verified by the mapping of the elements, performed by scanning electron microscopy and EDX analysis, the powders are chloride free, whereas silicon and M are homogeneously distributed. The M/Si ratio for the calcined samples are 0.93, 1.14, 1.64 and 1.62 for M=Zn, Mn, Ni and Co, respectively. The BET surface areas for the same previous sequence of powders are 33±3, 26±1.4, 20±0.2 and 43±0.2 m2 g−1, respectively.